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Transformer 40VA – 120/208/240V to 24V Replacement – NBK-20604
The NBK-20604 Transformer is a reliable replacement component used in HVAC systems requiring a 40VA step-down transformer to convert high-voltage input into a stable 24V output.
This transformer replaces Mars 50354 and is also compatible with Packard PF42440, making it an ideal solution for restoring proper low-voltage power to thermostats, relays, and control boards.
Key Features
- 40VA Power Rating: Suitable for many HVAC control applications
- Multi-Voltage Input: Supports 120V, 208V, and 240V primary connections
- 24V Output: Provides consistent low-voltage power for system controls
- Direct Replacement: Replaces Mars 50354 and Packard PF42440
- HVAC Ready: Designed for furnaces, air handlers, and other control circuits
Specifications
- SKU: 20604
- Category: HVAC, Miscellaneous
- OEM Brand: Mars
- Replaces OEM: 50354
- Voltage: 120/208/240V Primary → 24V Secondary
- Rating: 40VA
Direct Replacement For
- Mars: 50354
- Packard: PF42440
Why Choose NBK-20604?
The NBK-20604 Transformer ensures dependable low-voltage power delivery for HVAC control systems. It’s an essential replacement when troubleshooting power loss to thermostats, relays, or ignition/control boards.
Installation Tips
- Turn off all power at the breaker before installation.
- Confirm input voltage matches your system wiring (120V, 208V, or 240V).
- Secure transformer mounting to reduce vibration and wear.
- Check for proper 24V output before restoring full system operation.
- Consult a licensed technician if wiring is uncertain.
Pairs Well With
Thermostats, Control Boards, Ignition Modules, Limit Switches, HVAC Relays
SPECIAL ORDER NOTICE: This item is sourced through our special order program. Please allow 1–2 business days for processing prior to shipment.