PSH500A AC Power Supplies

Many of our past Tech Tuesday blogs have featured different RIB® relays that we produce. From the simple to the more “smart” relays, we offer quite a variety! Maybe you’re asking yourself: "Does Functional Devices make more than RIB® relays?" That’s a great question because we do! This week I would like to zoom in on some of our power supplies that are quite popular: the PSH500A family of AC power supplies.

The PSH500A

psh500aWhen customers voiced a desire to output power to multiple separate devices at 24Vac in a safe, Class 2 method, we introduced the PSH500A power supply. This power supply boasts a 500VA, multi-tap transformer that divides the output power of 24Vac to five individual outputs, each with 100VA of available power. The multi-tap primary has options for 480/277/240/120Vac input power. The behemoth of a transformer then steps down the input voltage to 24Vac at the output. Each 24Vac output has its own circuit breaker and ON/OFF switch to control specific outputs. There is also a red LED power indicator light for each output, providing a quick way of knowing if the output is on or off. All of this comes enclosed in a 12″ x 12″ metal enclosure.

Variations of the PSH500A

psmn500aIn true Functional Devices fashion, we listened to customer suggestions and tweaked the design to offer this device to more markets. First, there is the version without an enclosure: PSMN500A. The transformer and output power strip come mounted on a roughly 11″ x 11″ sub-panel with holes pre-drilled, making it ready to be fastened to your own enclosure.

The other variation of this power supply is model PSH500A-LVC. The “LVC” in this model name stands for “Low Voltage Compartment.” We’ve gone the extra step to separate the high voltage from the low voltage within the 12″ x 12″ enclosure, making it safer to access the 24Vac power outputs. This enclosure features two separate plate openings, each being fastened by its own hardware. The same electrical specifications exist for the “-LVC” model as the PSH500A and PSMN500A versions.

Applications of this Power Supply

So where could a power supply of this kind be used? We have heard many HVAC engineers making use of the PSH500A power supplies in VAV (variable air volume) systems. With five separate outputs, 24Vac may be supplied to each HVAC controller that controls the air supply to each room. We have also heard of these AC power supplies being installed in surgery rooms to help power the controls that keep those rooms free of airborne contaminants. There is also a use for these power supplies in a hospital or other scientific laboratory to supply power to hood ventilation controls, damper controls, or other loads that help to make the laboratory a safe place for handling chemicals or other potentially dangerous substances.

I hope this week’s blog entry helped to give a nice introduction to the PSH500A family of power supplies. It was a general description, so feel free to give us a call or send in an email to technical support if you would like to know more specific details of these power supplies. I or any of the other engineers would be more than happy to help!

About the Author

Meet Samuel Klennert - you can call him Sam. He was born and raised amongst the farmland of Indiana, which included corn, soy beans, and sometimes wheat. Sam graduated from Purdue University with a Bachelors degree in Electrical and Computer Engineering Technology in 2015. He has a focus in analog circuitry and power electronics, but he'll give digital a try from time to time - just not that digital witchcraft!

Outside of work, Sam enjoys outdoor activities including (but not limited to) hiking, mountain biking (or just really-big-hill biking), and camping. Call Sam for tech support today – he aims to please and will give his best effort to any task at hand!