{"id":16733,"date":"2026-08-26T08:00:00","date_gmt":"2026-08-26T00:00:00","guid":{"rendered":"https:\/\/www.wehopower.com\/?post_type=news&#038;p=16733"},"modified":"2026-08-31T14:20:31","modified_gmt":"2026-08-31T06:20:31","slug":"power-supply-for-cctv-cameras-12v-vs-24v-selection-guide","status":"publish","type":"news","link":"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/","title":{"rendered":"Fonte de alimenta\u00e7\u00e3o para c\u00e2meras de CFTV: Guia de sele\u00e7\u00e3o de 12V vs 24V"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_86 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">\u00cdndice<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Alternar \u00edndice de conte\u00fado\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Alternar<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewbox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewbox=\"0 0 24 24\" version=\"1.2\" baseprofile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Introduction\" >Introdu\u00e7\u00e3o<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#First_Rule_Match_the_Camera_Input_Specification\" >Primeira regra: Corresponder \u00e0 especifica\u00e7\u00e3o de entrada da c\u00e2mera<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#12V_and_24V_at_the_Same_Power\" >12V e 24V com a mesma pot\u00eancia<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Why_Voltage_Drop_Often_Decides_Between_12V_and_24V\" >Por que a queda de tens\u00e3o geralmente decide entre 12V e 24V<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Do_Not_Compensate_Blindly_by_Raising_the_Supply_Voltage\" >N\u00e3o compense cegamente aumentando a tens\u00e3o de fornecimento<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Build_a_Complete_CCTV_Power_Budget\" >Crie um or\u00e7amento completo de energia de CFTV<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Centralized_Local_or_Distributed_Power\" >Poder centralizado, local ou distribu\u00eddo<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Centralized_Security_Power_Supply\" >Fornecimento de energia de seguran\u00e7a centralizado<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Local_Power_Adapters\" >Adaptadores de pot\u00eancia locais<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Distributed_Low-Voltage_Cabinets\" >Gabinetes de baixa tens\u00e3o distribu\u00eddos<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Power_over_Ethernet\" >Pot\u00eancia sobre Ethernet<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Matching_the_Architecture_to_WEHO_Power_Supply_Families\" >Combinando a arquitetura com as fam\u00edlias de fornecimento de energia da WEHO<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Battery_Backup_and_Required_Runtime\" >Backup de bateria e tempo de execu\u00e7\u00e3o necess\u00e1rio<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Protection_Grounding_and_Surge_Control\" >Prote\u00e7\u00e3o, aterramento e controle de surtos<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Cable_and_Connector_Practices\" >Pr\u00e1ticas de cabos e conectores<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Commissioning_Checklist\" >Checklist de comissionamento<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Common_Selection_Mistakes\" >Erros comuns de sele\u00e7\u00e3o<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Assuming_Every_Camera_Uses_12VDC\" >Supondo que todas as c\u00e2meras usem 12VDC<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Sizing_From_Daytime_Current\" >Dimensionamento da Corrente Di\u00e1ria<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Ignoring_the_Return_Conductor\" >Ignorando o condutor de retorno<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Using_One_Large_Fuse_for_Small_Camera_Wires\" >Usando um fus\u00edvel grande para pequenos fios de c\u00e2mera<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Mixing_AC_and_DC_Ratings\" >Mixagem de AC e DC Ratings<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-23\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#FAQs\" >Perguntas frequentes<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-24\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Is_24V_always_better_for_long_CCTV_cable_runs\" >24V \u00e9 sempre melhor para longas corridas de cabo CCTV?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-25\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Can_I_power_a_12V_camera_from_a_24V_supply_with_a_resistor\" >Posso alimentar uma c\u00e2mera de 12V a partir de uma fonte de 24V com um resistor?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-26\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#How_much_spare_capacity_should_a_CCTV_power_supply_have\" >Quanta capacidade de reposi\u00e7\u00e3o deve ter uma fonte de alimenta\u00e7\u00e3o de CFTV?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-27\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Should_every_camera_have_a_separate_fuse\" >Todas as c\u00e2meras devem ter um fus\u00edvel separado?<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-28\" href=\"https:\/\/www.wehopower.com\/pt\/news\/power-supply-for-cctv-cameras-12v-vs-24v-selection-guide\/#Conclusion\" >Conclus\u00e3o<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"Introduction\"><\/span>Introdu\u00e7\u00e3o<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<figure class=\"weho-blog-image\"><img decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/08\/01-hero-cctv-power-room.png?quality=85&strip=all\" alt=\"Power Supply for CCTV Cameras: 12V vs 24V Selection Guide  title=\" loading=\"lazy\" power supply for cctv cameras: 12v vs 24v selection guide title=\"\"><\/figure>\n<p>Uma c\u00e2mera de CFTV pode reiniciar, perder a ilumina\u00e7\u00e3o infravermelha, produzir v\u00eddeo inst\u00e1vel ou cair do gravador quando sua tens\u00e3o de alimenta\u00e7\u00e3o cai abaixo da faixa permitida. A escolha entre 12V e 24V, portanto, afeta mais do que a etiqueta da fonte de alimenta\u00e7\u00e3o: ela muda a corrente, a queda de tens\u00e3o do cabo, a arquitetura de distribui\u00e7\u00e3o, o projeto de backup, a prote\u00e7\u00e3o e a capacidade de expans\u00e3o.<\/p>\n<p>A voltagem correta \u00e9 sempre a aceita pela c\u00e2mera e seus acess\u00f3rios. Uma c\u00e2mera somente de 12V n\u00e3o deve ser conectada a 24V e um dispositivo somente de 24V pode n\u00e3o funcionar corretamente a partir de 12V. Uma vez confirmada a compatibilidade, os instaladores podem comparar fontes centralizadas e locais, calcular a pior carga poss\u00edvel, e determinar se a distribui\u00e7\u00e3o de 24V oferece uma vantagem em longas tiragens. Este guia explica esse processo e mostra onde a distribui\u00e7\u00e3o de 24V da WEHO oferece uma vantagem em longas tiragens <a href=\"https:\/\/www.wehopower.com\/pt\/product-category\/security-power-supply\/\">Fam\u00edlias de abastecimento de energia de seguran\u00e7a<\/a> Adapte-se a um design de CFTV profissional.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"First_Rule_Match_the_Camera_Input_Specification\"><\/span>Primeira regra: Corresponder \u00e0 especifica\u00e7\u00e3o de entrada da c\u00e2mera<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Inspecione a etiqueta da c\u00e2mera e folha de dados para o tipo de tens\u00e3o, faixa permitida, polaridade, conector, corrente m\u00e1xima e m\u00e9todo de alimenta\u00e7\u00e3o. equipamentos de CFTV podem usar 12VDC, 24VAC, 24VDC, Power over Ethernet, ou uma entrada de tens\u00e3o dupla. Estes n\u00e3o s\u00e3o intercambi\u00e1veis apenas porque o n\u00famero \u201c24\u201d aparece em ambos os produtos.<\/p>\n<p>Verifique os acess\u00f3rios separadamente. Uma caixa aquecida, mecanismo pan-tilt-zoom, iluminador infravermelho, microfone, ponte sem fio e codificador podem ter diferentes requisitos de energia da c\u00e2mera. Use a demanda m\u00e1xima na condi\u00e7\u00e3o de opera\u00e7\u00e3o mais exigente. LEDs infravermelhos geralmente ligam \u00e0 noite, aquecedores come\u00e7am em clima frio e motores PTZ se movem intermitentemente; a fonte de alimenta\u00e7\u00e3o deve lidar com a combina\u00e7\u00e3o que pode ocorrer em conjunto.<\/p>\n<p>Se uma c\u00e2mera aceita uma ampla faixa, como 12 - 24VDC, use as instru\u00e7\u00f5es do fabricante para selecionar a tens\u00e3o nominal preferida. Nunca infere compatibilidade do formato do conector ou de outra c\u00e2mera da mesma s\u00e9rie.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"12V_and_24V_at_the_Same_Power\"><\/span>12V e 24V com a mesma pot\u00eancia<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Para uma dada pot\u00eancia de carga, o aumento da tens\u00e3o de distribui\u00e7\u00e3o reduz a corrente:<\/p>\n<p><strong>Corrente = Pot\u00eancia\/Voltagem<\/strong><\/p>\n<p>Uma c\u00e2mera de 12W desenha idealmente 1A a 12V, mas apenas 0,5 A a 24V. Corrente mais baixa reduz a tens\u00e3o perdida em um cabo e o calor produzido pela resist\u00eancia do condutor. Como a perda de energia do cabo \u00e9 proporcional \u00e0 corrente ao quadrado, a diferen\u00e7a pode se tornar importante em longas tiragens ou quando v\u00e1rias c\u00e2meras compartilham um tronco.<\/p>\n<p>Isso n\u00e3o significa que 24V \u00e9 automaticamente melhor. Compatibilidade da c\u00e2mera, AC versus DC, suprimentos dispon\u00edveis, requisitos de c\u00f3digo, equipamentos de backup, conectores e pr\u00e1ticas de servi\u00e7o s\u00e3o importantes. Muitas c\u00e2meras compactas s\u00e3o projetadas especificamente para 12VDC ou PoE. Um sistema de 12V bem projetado com tiragens curtas pode ser totalmente apropriado.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Why_Voltage_Drop_Often_Decides_Between_12V_and_24V\"><\/span>Por que a queda de tens\u00e3o geralmente decide entre 12V e 24V<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<figure class=\"weho-blog-image\"><img decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/08\/02-long-run-voltage-testing.png?quality=85&strip=all\" alt=\"Power Supply for CCTV Cameras: 12V vs 24V Selection Guide  title=\" loading=\"lazy\" power supply for cctv cameras: 12v vs 24v selection guide title=\"\"><\/figure>\n<p>Cada cabo tem resistance. The c\u00e2mera recebe a tens\u00e3o de alimenta\u00e7\u00e3o menos a queda em ambos os condutores de sa\u00edda e retorno:<\/p>\n<p><strong>Queda de tens\u00e3o = corrente \u00d7 resist\u00eancia total do circuito<\/strong><\/p>\n<p>Suponha que uma carga de 12W seja conectada atrav\u00e9s de um caminho de cabo com resist\u00eancia total de 1,2 \u03a9. Em 12V e 1A, a queda te\u00f3rica \u00e9 de 1,2 V, deixando cerca de 10,8 V antes das toler\u00e2ncias do conector e da fonte. Em 24V e 0,5 A, a queda \u00e9 de 0,6 V, deixando cerca de 23,4 V. O ramo de 24V tem mais margem, assumindo que a c\u00e2mera foi projetada para 24V.<\/p>\n<p>Calcule cada corrida do material condutor, \u00e1rea de se\u00e7\u00e3o transversal, comprimento de loop completo, corrente esperada, temperatura ambiente e tens\u00e3o de entrada m\u00ednima da c\u00e2mera. Me\u00e7a a tens\u00e3o na c\u00e2mera enquanto infravermelho, aquecedor, PTZ e outras cargas m\u00e1ximas est\u00e3o ativas. Medir um cabo descarregado pode ocultar a queda real.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Do_Not_Compensate_Blindly_by_Raising_the_Supply_Voltage\"><\/span>N\u00e3o compense cegamente aumentando a tens\u00e3o de fornecimento<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Algumas fontes permitem um ajuste limitado, mas o aumento da sa\u00edda para superar a queda do cabo pode sobrecarregar as c\u00e2meras pr\u00f3ximas ou um circuito levemente carregado. Mantenha a alimenta\u00e7\u00e3o dentro das classifica\u00e7\u00f5es do equipamento e resolva a queda excessiva com o tamanho apropriado do cabo, uma tens\u00e3o de distribui\u00e7\u00e3o compat\u00edvel mais alta, uma fonte local mais pr\u00f3xima ou uma arquitetura de energia diferente.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Build_a_Complete_CCTV_Power_Budget\"><\/span>Crie um or\u00e7amento completo de energia de CFTV<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Liste todos os dispositivos alimentados e sua demanda de pior caso. Use valores m\u00e1ximos de folha de dados em vez de consumo t\u00edpico.<\/p>\n<table class=\"weho-blog-table\">\n<thead>\n<tr>\n<th>Exemplo de equipamento<\/th>\n<th>Quantidade<\/th>\n<th>Pot\u00eancia m\u00e1xima de cada<\/th>\n<th>Subtotal<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>C\u00e2mera fixa IR<\/td>\n<td>8<\/td>\n<td>8 \u00aa W<\/td>\n<td>64 \u00aa W<\/td>\n<\/tr>\n<tr>\n<td>PTZ camera<\/td>\n<td>2<\/td>\n<td>24W<\/td>\n<td>48 \u00ba W<\/td>\n<\/tr>\n<tr>\n<td>Wireless bridge<\/td>\n<td>1<\/td>\n<td>12W<\/td>\n<td>12W<\/td>\n<\/tr>\n<tr>\n<td>Environmental housing heater<\/td>\n<td>2<\/td>\n<td>15 \u00aa W<\/td>\n<td>30W<\/td>\n<\/tr>\n<tr>\n<td><strong>Example total<\/strong><\/td>\n<td><\/td>\n<td><\/td>\n<td><strong>154W<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Add suitable headroom for supply temperature, aging, cable loss, startup events, and future channels. A 25% planning allowance would make the example target approximately 193W, but dynamic loads still need a separate peak-current check. If the power supply has multiple outputs, verify both the total rating and the maximum current permitted on each channel.<\/p>\n<p>The recorder, network switch, monitor, storage, and control equipment may require their own protected AC or DC circuits. Do not combine them into the camera calculation unless they are actually powered from the same supply.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Centralized_Local_or_Distributed_Power\"><\/span>Poder centralizado, local ou distribu\u00eddo<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3><span class=\"ez-toc-section\" id=\"Centralized_Security_Power_Supply\"><\/span>Fornecimento de energia de seguran\u00e7a centralizado<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>A central enclosure simplifies backup, branch fusing, service access, and monitoring. Each camera should have a protected output or a properly coordinated branch device. Centralized 12V works best when runs and currents remain within the voltage-drop budget. Centralized 24V can support longer runs when the cameras accept it.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Local_Power_Adapters\"><\/span>Adaptadores de pot\u00eancia locais<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Placing an adapter near each camera reduces low-voltage cable distance, but it creates many AC connection points and may complicate backup power, weather protection, maintenance, and tamper resistance. For small indoor systems, a suitable approved <a href=\"https:\/\/www.wehopower.com\/pt\/product-category\/power-adapter\/\">WEHO power adapter<\/a> can be practical when its connector, voltage, current, environment, and regulatory requirements match the camera.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Distributed_Low-Voltage_Cabinets\"><\/span>Gabinetes de baixa tens\u00e3o distribu\u00eddos<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Large sites can use several protected distribution points, each located near a camera group. This limits cable drop while retaining centralized branch control within each zone. The upstream design must coordinate AC supply, surge protection, grounding, battery backup, and communication pathways.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Power_over_Ethernet\"><\/span>Pot\u00eancia sobre Ethernet<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>PoE delivers data and power on network cabling and can simplify IP camera installations. Its power class, switch budget, cable length, temperature, redundancy, and surge protection must still be engineered. A Blog comparing 12V and 24V does not replace the camera and switch manufacturer&#8217;s PoE requirements.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Matching_the_Architecture_to_WEHO_Power_Supply_Families\"><\/span>Combinando a arquitetura com as fam\u00edlias de fornecimento de energia da WEHO<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<figure class=\"weho-blog-image\"><img decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/08\/03-security-power-supply-cabinet.png?quality=85&strip=all\" alt=\"Power Supply for CCTV Cameras: 12V vs 24V Selection Guide  title=\" loading=\"lazy\" power supply for cctv cameras: 12v vs 24v selection guide title=\"\"><\/figure>\n<p>WEHO&#8217;s <a href=\"https:\/\/www.wehopower.com\/pt\/product-category\/security-power-supply\/\">Security Power Supply category<\/a> is the most relevant landing page for centralized camera and access-control applications. It includes two useful system directions:<\/p>\n<ul>\n<li><a href=\"https:\/\/www.wehopower.com\/pt\/product_category\/security-power-supply\/sc-series-for-battery-charger-power-supply\/\">SC Series battery-charger power supplies<\/a> provide security-oriented power and battery-charging functions for compatible backup architectures.<\/li>\n<li><a href=\"https:\/\/www.wehopower.com\/pt\/product_category\/security-power-supply\/ad-series-ups-power-supply\/\">AD Series UPS power supplies<\/a> combine load delivery with battery-backup functionality for security systems.<\/li>\n<\/ul>\n<p>For a high-capacity AC-DC branch where an enclosed supply is appropriate, WEHO also offers 12V and 24V versions across its <a href=\"https:\/\/www.wehopower.com\/pt\/product_category\/enclosed-switching-power-supply\/\">enclosed switching power supply families<\/a>. One example is the <a href=\"https:\/\/www.wehopower.com\/pt\/product\/power-supply-12v-24v-36v-48v-500w-switching-power-supply-for-led-strip-cctv-camera\/\">LRS-500 series<\/a>, available in 12V and 24V variants for larger load groups. Selection must consider enclosure, cooling, terminal guarding, branch protection, backup requirements, and the relevant safety approvals for the final installation.<\/p>\n<p>Choose voltage first from camera compatibility and cable design. Then choose the supply family from total load, channel arrangement, backup time, alarm functions, environment, installation method, and service requirements. A high wattage alone does not make a product suitable for a particular CCTV site.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Battery_Backup_and_Required_Runtime\"><\/span>Backup de bateria e tempo de execu\u00e7\u00e3o necess\u00e1rio<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Security systems often need to remain active during a power failure. Define which cameras, recorders, switches, communications links, and access-control devices are critical. Calculate their energy demand in watt-hours:<\/p>\n<p><strong>Required load energy = total critical power \u00d7 backup hours<\/strong><\/p>\n<p>A 120W critical load operating for four hours ideally requires 480Wh. The battery must be larger after accounting for conversion losses, allowable depth of discharge, temperature, aging, discharge rate, charger recovery, and reserve margin. Lead-acid and lithium batteries have different charging and protection requirements.<\/p>\n<p>Use a security power supply or UPS architecture designed for the chosen battery chemistry. Do not attach a battery directly to an ordinary fixed-output supply unless the system is specifically designed and documented for charging, low-voltage protection, and transfer behavior.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Protection_Grounding_and_Surge_Control\"><\/span>Prote\u00e7\u00e3o, aterramento e controle de surtos<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Protect the AC input and every low-voltage branch according to the conductor and equipment ratings. A multi-channel cabinet with individually protected outputs helps prevent one cable fault from disabling the entire system. Select DC-rated fuses or breakers where DC interruption is required.<\/p>\n<p>Outdoor camera cables can carry surge energy into the building. Follow the site design for surge protection, bonding, earthing, shield termination, and separation from mains conductors. Avoid creating ground loops between camera housings, power returns, coaxial shields, network equipment, and structural metal.<\/p>\n<p>Power-supply internal overvoltage or overload protection does not replace external surge protection or branch cable protection. Requirements depend on the installation location, building rules, lightning exposure, and equipment approvals.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Cable_and_Connector_Practices\"><\/span>Pr\u00e1ticas de cabos e conectores<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Use conductor size calculated for current and full loop distance. Check terminal and connector ratings, especially on high-current centralized outputs. Barrel connectors can look identical while using different polarity or dimensions. Label circuits at both ends and document the camera served by each branch.<\/p>\n<p>Keep low-voltage power away from mains wiring as required. Support cables so their weight does not pull on camera or supply terminals. In outdoor locations, use suitable glands, drip loops, sealed junction boxes, corrosion-resistant connectors, and strain relief. A weather-resistant camera does not make an exposed power connection weather-resistant.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Commissioning_Checklist\"><\/span>Checklist de comissionamento<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<figure class=\"weho-blog-image\"><img decoding=\"async\" src=\"https:\/\/i1.wp.com\/www.wehopower.com\/wp-content\/uploads\/2026\/08\/04-cctv-system-commissioning.png?quality=85&strip=all\" alt=\"Power Supply for CCTV Cameras: 12V vs 24V Selection Guide  title=\" loading=\"lazy\" power supply for cctv cameras: 12v vs 24v selection guide title=\"\"><\/figure>\n<ol>\n<li>Verify the voltage type and allowable range for every camera and accessory.<\/li>\n<li>Confirm calculated total load, peak demand, and per-channel current.<\/li>\n<li>Check power-supply input selection and protective earth before energizing.<\/li>\n<li>Measure unloaded output voltage and polarity at the distribution cabinet.<\/li>\n<li>Connect one branch at a time and confirm that its protection is correctly identified.<\/li>\n<li>Measure camera-terminal voltage in daytime and with IR illumination, heaters, and PTZ movement active.<\/li>\n<li>Confirm stable video and network operation during the highest combined demand.<\/li>\n<li>Test mains-failure transfer, battery operation, alarms, and low-voltage shutdown where applicable.<\/li>\n<li>Inspect supply, terminals, branch fuses, and cables for abnormal heating after an extended run.<\/li>\n<li>Record voltage and current readings as a maintenance baseline.<\/li>\n<\/ol>\n<h2><span class=\"ez-toc-section\" id=\"Common_Selection_Mistakes\"><\/span>Erros comuns de sele\u00e7\u00e3o<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3><span class=\"ez-toc-section\" id=\"Assuming_Every_Camera_Uses_12VDC\"><\/span>Supondo que todas as c\u00e2meras usem 12VDC<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Cameras can use 12VDC, 24VAC, 24VDC, PoE, or dual-voltage inputs. Read the exact model documentation.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Sizing_From_Daytime_Current\"><\/span>Dimensionamento da Corrente Di\u00e1ria<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Infrared LEDs, heaters, and PTZ motors may create the worst load at night or in cold weather.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Ignoring_the_Return_Conductor\"><\/span>Ignorando o condutor de retorno<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Voltage-drop calculations must include both outgoing and return paths.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Using_One_Large_Fuse_for_Small_Camera_Wires\"><\/span>Usando um fus\u00edvel grande para pequenos fios de c\u00e2mera<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>A main fuse sized for the total supply may not protect an individual branch. Coordinate protection per circuit.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Mixing_AC_and_DC_Ratings\"><\/span>Mixagem de AC e DC Ratings<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>A device rated for 24VAC is not automatically compatible with 24VDC. Confirm voltage type and range.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"FAQs\"><\/span>Perguntas frequentes<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3><span class=\"ez-toc-section\" id=\"Is_24V_always_better_for_long_CCTV_cable_runs\"><\/span>24V \u00e9 sempre melhor para longas corridas de cabo CCTV?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>It generally reduces current and voltage drop for the same power, but only when the camera accepts the specific 24V supply type. Cable calculation and camera limits remain mandatory.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Can_I_power_a_12V_camera_from_a_24V_supply_with_a_resistor\"><\/span>Posso alimentar uma c\u00e2mera de 12V a partir de uma fonte de 24V com um resistor?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>No. Camera current changes with operating mode, so a series resistor cannot provide reliable regulation. Use the correct 12V supply or a properly rated DC-DC converter at the load.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"How_much_spare_capacity_should_a_CCTV_power_supply_have\"><\/span>Quanta capacidade de reposi\u00e7\u00e3o deve ter uma fonte de alimenta\u00e7\u00e3o de CFTV?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Start from verified maximum simultaneous demand and add engineering allowance for losses, temperature, peaks, and expansion. The correct margin depends on camera behavior and supply specifications; a peak check is still required.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Should_every_camera_have_a_separate_fuse\"><\/span>Todas as c\u00e2meras devem ter um fus\u00edvel separado?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Individual branch protection is generally preferable in centralized systems because it protects smaller conductors and limits the effect of one fault. Follow the cabinet and local installation requirements.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Conclusion\"><\/span>Conclus\u00e3o<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>The choice between 12V and 24V CCTV power begins with camera compatibility and ends with a complete system check. Calculate maximum load, nighttime and heater demand, cable voltage drop, branch protection, backup runtime, environment, grounding, and surge exposure. Twelve volts is practical for many short, compatible runs; 24V can reduce current and improve long-run margin when the cameras explicitly support it.<\/p>\n<p>Explore the <a href=\"https:\/\/www.wehopower.com\/pt\/product-category\/security-power-supply\/\">WEHO Security Power Supply range<\/a> ou <a href=\"https:\/\/www.wehopower.com\/pt\/contact\/\">contact WEHO<\/a> with camera models, quantities, cable lengths, required voltage type, backup hours, and installation conditions for product selection support.<\/p>","protected":false},"excerpt":{"rendered":"<p>Compare os sistemas de energia de CFTV de 12V e 24V, calcule a carga da c\u00e2mera e a queda de tens\u00e3o e escolha energia centralizada, local ou com suporte de bateria.<\/p>","protected":false},"author":1,"featured_media":16729,"parent":0,"menu_order":190,"comment_status":"closed","ping_status":"","template":"","format":"standard","meta":{"_acf_changed":false,"_joinchat":[],"footnotes":""},"news_category":[149,148],"class_list":["post-16733","news","type-news","status-publish","format-standard","has-post-thumbnail","hentry","news_category-blog","news_category-industry-news","entry"],"acf":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.wehopower.com\/pt\/wp-json\/wp\/v2\/news\/16733","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wehopower.com\/pt\/wp-json\/wp\/v2\/news"}],"about":[{"href":"https:\/\/www.wehopower.com\/pt\/wp-json\/wp\/v2\/types\/news"}],"author":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/pt\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/pt\/wp-json\/wp\/v2\/comments?post=16733"}],"version-history":[{"count":1,"href":"https:\/\/www.wehopower.com\/pt\/wp-json\/wp\/v2\/news\/16733\/revisions"}],"predecessor-version":[{"id":16750,"href":"https:\/\/www.wehopower.com\/pt\/wp-json\/wp\/v2\/news\/16733\/revisions\/16750"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.wehopower.com\/pt\/wp-json\/wp\/v2\/media\/16729"}],"wp:attachment":[{"href":"https:\/\/www.wehopower.com\/pt\/wp-json\/wp\/v2\/media?parent=16733"}],"wp:term":[{"taxonomy":"news_category","embeddable":true,"href":"https:\/\/www.wehopower.com\/pt\/wp-json\/wp\/v2\/news_category?post=16733"}],"curies":[{"name":"wp ent\u00e3o","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}