Tempstar 40VA Transformer for TCA748GKA100 — 208/230V to 24V Control Transformer | Ships Today
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Overview
This OEM control transformer (part number 1170676) steps the Tempstar TCA748GKA100's 208/230V line voltage down to the 24V used by the contactor coil, control circuit, and thermostat. Rated at 40VA, it supplies the low-voltage power that energizes the unit when a cooling call comes from the thermostat. A burned-out transformer is one of the most common causes of a completely dead control circuit: the compressor and condenser fan won't start, and the thermostat may go blank if it draws power from the same circuit. Failures usually trace back to a shorted secondary, a stuck contactor drawing excess current, or repeated voltage spikes.
Specifications
| Spec | Value |
|---|---|
| Part Number | 1170676 |
| Type | Control Transformer |
| Brand | Tempstar (ICP / Heil) |
| Rating | 40VA |
| Primary Voltage | 208/230V |
| Secondary Voltage | 24V |
| Fits Model | TCA748GKA100 |
Compatibility
Direct-fit replacement for the Tempstar TCA748GKA100 condensing unit. The 1170676 40VA transformer is used across many ICP-family condensers and air handlers under the Tempstar, Heil, Comfortmaker, and ICP brands. Verify your primary and secondary voltages and the existing part number before ordering.
Installation Guide
- Safety First — Disconnect power at the disconnect and breaker, then verify zero voltage with a multimeter.
- Access — Remove the condenser service/control panel.
- Document — Photograph the primary and secondary wiring before disconnecting.
- Remove — Disconnect the leads, then unbolt the transformer from its mounting bracket.
- Install — Mount the new transformer and reconnect primary (line) and secondary (24V) leads exactly per your photo.
- Test — Restore power and confirm 24V across the secondary and normal unit operation on a cooling call.
Signs You Need a Replacement
- No 24V control power — compressor and fan won't energize on a cooling call.
- Thermostat goes blank or loses power.
- Burnt smell, discolored windings, or visible scorching on the transformer.
- Measured 0V at the secondary with correct line voltage at the primary.
Shipping & Returns
Ships same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.
Shipping Information
- Orders placed before 3PM CST ship same business day
- Standard delivery: 2-5 business days
- Express shipping available at checkout
- Free shipping on orders over $75
- Tracking number emailed upon shipment
Return Policy
- 30-day returns on unused parts in original packaging
- Electrical parts (capacitors, contactors, control boards) are final sale once installed
- Email info@nationalhvacparts.com to initiate a return
- Refunds processed within 5-7 business days