A battery testing power supply request can describe two different circuits: the instrument that exchanges energy with the pack, and the auxiliary branch that keeps rack electronics operating. Specify them separately.
A charge-discharge rack may contain programmable test instruments, pack fixtures, interface boards and an acquisition or control system. The word “power supply” is too broad to identify which circuit is being purchased. A fixed-voltage source associated with the rack does not become the battery cycler merely because both appear in the same equipment photograph.
This article uses the exact WEHO NDR-120-24 as a conditional example for separately documented rack electronics accepting a compatible 24 V input. Battery charge and discharge energy belongs to a separately specified test instrument and fixture arrangement. No cell count, chemistry, pack capacity, test-current profile or successful cycle has been assumed.
Define the test channel and the auxiliary branch independently
The test-channel brief should identify the actual instrument, pack interface, allowed operating range and test procedure supplied by the responsible equipment team. That instrument’s capabilities determine whether it can perform the required charge, discharge or energy-handling tasks. The NDR-120-24 example in this article is not assigned those capabilities and is not connected directly to battery contacts in the illustrations.
The auxiliary branch brief is different. It identifies the actual rack electronics that require power, their permitted input limits, connection references and relevant demand states. Those receivers might have a separate input from the test instrument’s energy terminals. The rack documentation, not visual proximity, establishes whether they belong to the same branch.
Keep the two interfaces separate in the wiring schedule and procurement documents. A board that exchanges commands with a cycler does not thereby receive its operating power from the cycler’s pack terminals. Conversely, an auxiliary supply’s fixed output does not establish a charge-control profile, a discharge energy path or a safe battery connection arrangement.
Record the exact 24 V source and the sample revision
ال official WEHO English NDR-120 model table identifies NDR-120-24 as a 24 V, 5 A output model. The exact approved sample is marked INPUT:100–240 VAC 2.6 A, 50/60 Hz, and OUTPUT:24 V followed by its original direct-current graphic and 5.0 A. Its approved drawing gives a 40 mm front width, 125.2 mm upright height and 113.5 mm front-to-rear envelope.
The current public input row and approved sheet do not supply one reconciled sample specification. Keep the physical nominal marking, approved sheet revision and public description separately attributed; do not combine their broadest values into a guarantee. This article does not assign generic plastic-case, relay-contact or thermal marketing language to the actual metal-cased sample. Obtain the applicable exact revision and input instructions before accepting the rack branch.
The output label is a model characteristic, not the measured consumption of the rack. It does not establish the number of pack positions, instrument channels or interface boards that may be operated. Those quantities remain outside this example until the actual receiver inventory and operating conditions are documented.
Build an auxiliary-receiver inventory by operating state
List the actual 24 V receivers with full identifier, document revision, input limits and connection point. Separate startup behavior from sustained demand where the receiver documentation provides that distinction. Record which devices remain active during an idle rack state, which change state with a test request and which have a different supply interface altogether.
The load record should remain traceable to those receiver documents. Do not infer demand from a rack’s size, a screen image or a battery pack capacity. A larger pack test does not automatically imply a larger auxiliary-electronics load, and an increased channel count should not be converted into an assumed current without the actual interface evidence.
Keep the source conditions, receiver limits and distribution design together. Actual conductor routes, protective arrangements and installation requirements belong to the qualified rack design. The source’s repeated positive and negative terminals do not turn it into several independently regulated or independently protected test channels.
Preserve the evidence chain through a rack event
If the rack reports a communication interruption or interface reset, preserve the actual operating state and original records before replacing the auxiliary source. Identify which receiver was affected and whether the test instrument continued, stopped or reported a separate condition. A controller log is not, by itself, a measured source-terminal voltage waveform.
Qualified investigation should keep source-terminal and receiver-input observations comparable in timing and scope. The record must state how the observation was obtained and what remains uncertain. This article supplies no reset threshold, transient trace, captured reading or proof that a particular source caused a battery-test interruption.
The auxiliary branch and the battery energy channel may influence the same test sequence while remaining different electrical circuits. That is precisely why the architecture drawing and instrument records matter. Keep their connection and control boundaries explicit instead of treating every test-rack symptom as an ordinary supply fault.
Use the complete rear-rail geometry and actual entry mouths
The complete approved mechanical drawing gives a 40 mm front width, 125.2 mm upright height and 113.5 mm depth. Its original rear fitting geometry supports a horizontal DIN rail fixed against the rack backplate behind the full housing. The rail is not a shelf under the source and must not pass through the center of the case. A narrow front face does not eliminate the depth and service-access requirements.
The physical sample has four upper DC connection points, printed −V, −V, +V and +V, and three lower input points printed protective earth, N and L. The visible front circular openings provide screw access. Source photographs and the drawing identify separate top and underside conductor entry mouths; the roof honeycomb holes are ventilation, not cable routes. The original voltage adjustment sits above the smaller DC OK indicator on this NDR-120 sample.
The laboratory-rack illustration shows a proposed connected auxiliary branch whose conductors route only to rack-electronics distribution. The second illustration shows a different end-of-line rack during mechanical-fit inspection before termination, with all four upper and three lower connection points empty. Neither scene establishes a powered charge-discharge test, accepted battery connection, verified hidden latch engagement or validated thermal operating orientation.
Make the rack procurement brief unambiguous
A useful procurement package has separate sections for the programmable test instrument, pack fixture and auxiliary source. For the latter, provide the exact full model, approved source photographs, sample revision, actual input condition, receiver inventory, connection map and mechanical drawing. Include the rack enclosure and service-access requirements without assigning the source an unsupported ingress or certification rating.
At receiving inspection, compare the original model, trademark, four-upper/three-lower terminal order, adjustment control and fixing geometry with the approved evidence. If the delivered revision differs, reconcile it before assembly. Do not modify a label or article statement to make an unsupported electrical capability appear valid.
Frequently asked questions
Is NDR-120-24 the battery charge-discharge instrument?
No such role is established here. It is a conditional candidate for documented 24 V rack electronics. The actual battery energy channel requires its own instrument and fixture specifications.
Does 5.0 A establish the test rack’s channel count?
No. It is the exact source’s nominal output marking, not a pack-test current, receiver demand or channel-count approval.
Do the repeated upper DC connections create separate test channels?
No. The original four upper connection points have two negative and two positive markings, but that does not establish independently regulated channels or branch protection. The actual rack distribution and test-instrument design determine those functions.
Why is the second application not wired?
It illustrates a mechanical-fit stage before conductor termination in a different test rack, not a powered acceptance or successful battery cycle.
