---
title: Wiring a Thermostat with a Power Pack
description: Power packs simplify thermostat wiring by replacing transformers and controlling HVAC loads. See how the RIB21BPP5 makes HVAC automation easier.
image: https://blog.functionaldevices.com/hubfs/Imported_Blog_Media/Wiring_A_Thermostat-4.jpg
---

On this week's Tech Tuesday, we'll go over the simple wiring of using a power pack with a thermostat. While wiring up a thermostat isn't exactly difficult, using a power pack in place of a transformer can definitely make it easier. That's not even counting the potential time and money saved though using one.

[![Built for Professionals. Reliable RIB components to boost installation efficiency | Let's Talk »](https://no-cache.hubspot.com/cta/default/46049000/interactive-186799080867.png) ](https://blog.functionaldevices.com/hs/cta/wi/redirect?encryptedPayload=AVxigLJNRgDkuicENOAPR8LAbOk733PJggTeA%2BEIcUXILpyEYuJ8papATB0cBSTQzEFFd4qA84HHOKW6RtcltpSM29XdagaME60kpmrsCcCzqOiFCPE3oqUWgnJjOi1ZeeYFtxoh5DO6L60SpTBujzqx%2B3gbfE3ZJq9yz1ESes6ckSZMieRONSApPL5nJ0W5zkAn6Y1pVNSWPaTGeOrMuf7ypicKtlTpHGSVrZ%2BXCKCX03hs03O7v8TZUzwMAS4cCKKWa02CrKgtEDWnKEk%3D&webInteractiveContentId=186799080867&portalId=46049000)

Instead of powering up an occupancy or vacancy sensor, a power pack can be used to power a thermostat directly, eliminating the need for a step-down transformer. On top of that, the call terminal on a thermostat can be connected to the control input of the power pack, making the power pack automatically control your heater or other HVAC load.

### Wiring diagram using our RIB21BPP5:

![Wiring diagram using our RIB21BPP5](https://blog.functionaldevices.com/hubfs/Imported_Blog_Media/powerpackthermostat-2.png "powerpackthermostat")

In addition to this, if more than one call is needed for different loads, the [RIB21BPP5](https://www.functionaldevices.com/product/rib21bpp5/) can power more relays such as the [RIBU1C](https://www.functionaldevices.com/product/ribu1c-relay/) or [RIB2401B](https://www.functionaldevices.com/product/rib2401b/), up to 5 Watts. Just connect the relay coil to its corresponding call on the thermostat. If more power is needed, we also have the [RIB21BPP10](https://www.functionaldevices.com/product/rib21bpp10/) that can supply a full 10W. And of course, if you have any other questions on this topic, be sure to call or email us at Tech Support.

[![Built for Professionals. Reliable RIB components to boost installation efficiency | Let's Talk »](https://no-cache.hubspot.com/cta/default/46049000/interactive-186799080867.png) ](https://blog.functionaldevices.com/hs/cta/wi/redirect?encryptedPayload=AVxigLJNRgDkuicENOAPR8LAbOk733PJggTeA%2BEIcUXILpyEYuJ8papATB0cBSTQzEFFd4qA84HHOKW6RtcltpSM29XdagaME60kpmrsCcCzqOiFCPE3oqUWgnJjOi1ZeeYFtxoh5DO6L60SpTBujzqx%2B3gbfE3ZJq9yz1ESes6ckSZMieRONSApPL5nJ0W5zkAn6Y1pVNSWPaTGeOrMuf7ypicKtlTpHGSVrZ%2BXCKCX03hs03O7v8TZUzwMAS4cCKKWa02CrKgtEDWnKEk%3D&webInteractiveContentId=186799080867&portalId=46049000)

**Read More From Our Most Recent Articles**: [Keeping Data Centers Cool: How HVAC Controls Improve Efficiency and Reduce Costs](https://blog.functionaldevices.com/hvac-controls-efficiency-cost-reduction)

## About Functional Devices, Inc.

![Confidence and Peace of Mind](https://blog.functionaldevices.com/hs-fs/hubfs/Imported_Blog_Media/Confidence-Sep-13-2024-03-57-24-8627-PM.jpg?width=1000&height=741&name=Confidence-Sep-13-2024-03-57-24-8627-PM.jpg)

Functional Devices, Inc., located in the United States of America, has been designing and manufacturing quality electronic devices since 1969. **Our mission is to enhance lives in buildings and beyond.** We do so by designing and manufacturing reliable, high-quality products for the building automation industry.  Our suite of product offerings include [RIB relays,](https://blog.functionaldevices.com/product-guidance/troubleshooting-rib-relays) current sensors, power controls, power supplies, transformers, lighting controls, and more.

**We test 100% of our products, which leads to less than 1 out of every 16,000 products experiencing a failure in the field.**

Simply put, we provide users of our various product confidence and peace of mind in every box.

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