Scope of this technical record
Model-family orientation for a Baldor Series 15H inverter control associated with a reviewed supply drawing and official hardware-fault terminology.
Do not assume that a circuit drawing labelled BALDOR 15H matches every physical Series 15H unit. Confirm model, frame and installed assembly identity before repair, replacement or measurement decisions.
Identity before diagnosis
Series-level names are not sufficient for component-level service. A Baldor Series 15H unit may be encountered through a catalogue identifier, enclosure variation, voltage rating or application-specific installation. This model-family page records the known connection: the official drive family exists, official fault terminology is available, and a reviewed drawing labelled BALDOR 15H reveals an auxiliary-power architecture relevant to fault routing.
The page intentionally does not convert the schematic into a universal spare-parts declaration. A field technician or repair buyer should provide the full nameplate and photos of installed assemblies before treating this circuit reference as an exact board match. That boundary protects against fitting a visually similar supply board to a different frame or revision.
What the reviewed drawing contributes
The drawing shows two conversion/control regions using UCC3802 and UCC3804 controllers. Each is associated with isolated regulation components including a TL431 reference and a CNY17-4 optocoupler. Secondary sections show rail labels that include +21 V, +29 V and bipolar +15 V / -15 V regulation via 7815 and 7915 devices.
These visible identifiers matter because an official HW Power Supply indication is not a repair answer. It is a starting point. The drawing makes it possible to organize whether the suspected problem lies in energy conversion, feedback regulation, derived-rail conditioning or downstream loading from control electronics.
Evidence boundary
| Known | Not yet asserted |
|---|---|
| Series 15H official fault terms | Specific board part-number compatibility for every drive |
| Drawing labelled BALDOR 15H | Universal applicability across all frames/revisions |
| Visible supply and feedback topology | A component failure without measurements and identity match |
Useful fault entries for this family
HW Power Supply is the closest direct link between the official diagnostic language and the reviewed power-supply schematic. The manual points to an internal supply malfunction and logic power board; the schematic then supplies a map of conversion and regulation regions that can be documented before a replacement control board is placed at risk.
HW Ground Fault and DC-bus events are also relevant, but they enter through different decisions. A ground-fault indication begins with motor and cable isolation rather than supply-board assumptions. BUS Overvoltage or Bus Undervoltage requires timing, input and load evidence before it becomes a board investigation.
Information required for an actionable request
A meaningful request should include full drive model, voltage class, fault message, timing, prior repairs, whether replacement boards have already failed, and clear photographs of assembly labels or visible damage. If the request involves a power-supply suspicion, it should also state whether the keypad initializes and whether the symptom changes under controlled isolation of downstream loads.
With those inputs, the database can mature from a family-level circuit reference into a verified assembly, failure mode or replacement-compatibility record. Without them, the responsible output is a diagnostic route, not an unsupported component prescription.
Field record checklist
- Nameplate and full catalogue identifier
- Drive voltage/input configuration
- Fault display and timing
- Assembly or board markings
- Prior replacement history
Technical basis and reference documents
This is an independent editorial technical reference. Original manufacturer documentation remains controlling for installation, repair and commissioning decisions.
Official source for Series 15H operating scope, fault terminology and first-line troubleshooting guidance.
Reviewed schematic identifying UCC3802/UCC3804, TL431/CNY17-4 feedback and derived low-voltage rails; original source drawing is not redistributed.
Related technical records
The Series 15H reports HW Power Supply, may fail to enable correctly, or may present unstable control behavior associated with its low-voltage electronics.
The drive declares HW Ground Fault during run request or output energization, requiring separation of motor/cable insulation failure from internal drive-side protection activity.
The Series 15H trips with BUS Overvoltage, often requiring separation of line conditions, deceleration regeneration and dynamic-braking or internal measurement issues.
The drive reports a low DC-bus condition or cannot maintain operation while the control electronics may still show status information.
A reviewed supply drawing identifies two controlled conversion regions using UCC3802 and UCC3804, supplying isolated low-voltage functions used by drive electronics.
The drawing shows TL431 reference and CNY17-4 optocoupler feedback elements in both controlled supply regions, creating a diagnostic boundary between output-rail error and switching-stage response.
The reviewed drawing exposes +21 V and +29 V secondary regions feeding a visible 7815 / 7915 bipolar regulator section and +15 V / -15 V outputs.
HW Power Supply indication, unstable control behavior or a suspected internal auxiliary-power failure.
HW Ground Fault appears at enable or while commanding motor output.
BUS Overvoltage or Bus Undervoltage appears during energization, acceleration, running or deceleration.