A hydraulic power unit supply question is not answered by the pump motor rating alone. Map the motor energy path, valve interfaces and controller circuits separately before selecting a source for any one branch.
A hydraulic press can contain a pump motor starter, control electronics, valve drivers and machine safety functions, each with a different electrical role. Treating the complete assembly as one DC load hides the interfaces that actually determine a supply choice. Begin with the equipment drawings and receiver documentation, not a convenient product photograph or an assumed “standard” valve voltage.
This guide uses the source-specific WEHO NDR-75-24 as a conditional example for a documented 24 V controller or interface branch in a protected dry compartment. It is not a recommendation to run the hydraulic pump motor from this supply. No solenoid count, valve coil demand, pump capacity, pressure capability or complete machine compatibility has been invented.
Build a power tree that keeps electrical roles visible
First identify where the pump motor receives its operating energy. Record the actual motor starter or drive arrangement and its approved feeder documentation separately from any low-voltage controller branch. A control output that requests a motor start is not the circuit that supplies the motor’s operating power. That distinction should remain clear in the purchasing brief and in the cabinet drawing.
Next identify the valve actuation path. The controller may command a separate driver, or a particular receiver may accept a direct electrical input; the actual documentation decides which arrangement exists. Do not assign a coil to a 24 V rail simply because the machine performs a familiar hydraulic function. Voltage type, permitted input limits, startup or holding demand and interface behavior remain receiver-specific facts.
Finally locate the sensing and control-electronics interfaces. A shared low-voltage branch can only be considered after the actual receivers, common-reference requirements and allowed interconnections are known. Keep a receiver list with its document revision and connection point. A missing specification is an open engineering action, not a load allowance that can be filled with a guessed current.
Use the exact source model, not a family name
Le official WEHO English NDR-75 product table identifies NDR-75-24 as a 24 V output model with a rated 3.2 A output. The approved exact sample carries that full model, INPUT:100–240 VAC 1.6 A, 50/60 Hz, and OUTPUT:24 V followed by the original direct-current graphic and 3.2 A. Its narrow front is 32 mm wide, upright height is 125.2 mm, and front-to-rear envelope is 102 mm.
The public table and approved sheet describe a broader operating input range than the physical sample’s nominal label. Keep each revision and the physical receiving record separate; this example does not combine the broadest values into a new guaranteed range. Generic public prose about case material, status relay contacts or thermal operation is not assigned to this metal-cased sample without exact revision evidence.
For the proposed installation, obtain the applicable input and receiver documents before accepting the branch. The rendered illustration is not a measurement of line voltage or a commissioning record. The original source has a status indicator and voltage adjustment; these are not a hydraulic safety controller, a valve driver or evidence that all machine interfaces are compatible.
Separate steady demand from machine events
For the proposed 24 V branch, collect the actual simultaneous receiver demand and the relevant operating states. Record which devices are continuously present, which change state together and which demand is described only during a transition. Keep the source conditions and receiver limits beside the calculation so a nominal output rating is not mistaken for a guarantee under every cabinet condition.
A valve switching event may coincide with a motor-start request or another machine action, but coincidence alone does not establish the cause of a controller reset. Record the sequence using actual evidence. If a symptom occurs, preserve the source-terminal, receiver-input and controller-state observations with their timing and measurement arrangement. Do not invent transient readings or claim a successful test from the illustration.
Distribution design is a separate task from source selection. The responsible machine designer must specify the actual branch conductors, protective arrangement, terminals and receiver interfaces. The four upper DC connection points and three lower input connection points do not establish separate protected hydraulic outputs. The NDR-75-24 source does not create a valve driver, a motor contactor or a machine safety function.
Keep the supply out of the hydraulic working environment
The source sample has a ventilated metal enclosure. It is shown here only in a protected dry electrical compartment separated from the oil reservoir, hoses and hydraulic manifold. That separation is an equipment-design requirement to resolve, not an IP rating or fluid-resistance property assigned to this supply. A photograph beside a hydraulic unit cannot prove suitability for oil spray, condensation or the temperature at a particular installation point.
Keep normal service access, conductor routing and enclosure ventilation in the layout review. The finished equipment’s actual instructions and conditions govern the final arrangement. Do not draw a wire through a ventilation hole to make a scene appear connected, and do not obstruct the source label or adjustment access to hide a mechanical-fit problem.
Check the complete rear-rail envelope
The complete approved drawing and authentic rear photograph support DIN-rail mounting through the original rear upper hooks and spring-loaded lower latch. The horizontal rail belongs against the machine backplate behind the complete 102 mm depth. It must not pass through the center of the housing or substitute for a shelf under the product. The 32 mm front width alone is not the mounting envelope.
The metal front, actual top and bottom conductor entry mouths, ventilation pattern and rear fitting relationship are part of the receiving check. A left-side photograph and one mechanical-sheet hole annotation differ; these illustrations deliberately use the supported near-front projection rather than claim a conclusion about that disputed face. This is not a basis to erase a source inspection label or invent a blank side.
The hydraulic-press illustration is a proposed connected control-interface branch in a separate dry compartment. The lifting-table illustration shows a different machine and mechanical-fit inspection before conductor termination. Empty clamps in that second scene do not mean an energized lifting-table installation. Neither image proves hidden latch engagement, an accepted operating orientation, branch protection or finished equipment compatibility.
Make the purchasing handoff specific
A useful RFQ separates the complete hydraulic unit from the selected electrical source. Identify the exact full model and sample revision, the proposed branch, actual receiver documentation, source input condition, rear-mounting drawing and enclosure boundary. Keep unanswered receiver or input questions in the open-action list rather than assigning them to a supplier as an unstated requirement.
The receiving check should compare the physical nameplate, terminal order, exact input markings and rear fixing geometry with the approved evidence. A similar-looking enclosure is not enough. If the actual product or revision differs, reconcile the difference before assembly; do not change the article’s wording to make an incorrect label or invented mounting feature look acceptable.
Frequently asked questions
Can NDR-75-24 power the complete hydraulic power unit?
This guide does not establish that. It considers only a separately documented 24 V controller or interface branch. Pump-motor energy and any valve actuation requirements must be identified and qualified independently.
Can I assume every hydraulic valve is a 24 V DC load?
No. Use the exact receiver documentation for voltage, limits, current behavior and the required driver interface. Familiar machine behavior is not electrical evidence.
Does a rear-rail illustration prove the installation is accepted?
No. The original rear hook and latch evidence supports the depicted mounting relationship, but the equipment assembly record must still resolve actual engagement, spacing, input conditions, receiver interfaces and installation instructions.
Why does the second application have no supply wires?
It depicts mechanical fit before conductor termination in a different lifting-table control compartment. It does not claim energized operation, measured performance or finished equipment approval.
