A Common Commercial Mishap - How to Set a Transformer for 208V

This video covers A Common Commercial Mishap. How to tap a transformer for 208 volts instead of 240 volts on an air conditioning system installed in a commercial application featuring Eric Mele.

Read all the tech tips, take the quizzes

[bikerbobcat]

Good video and IMPORTANT! I've seen this destroy commercial package variable speed fan motors. I got called out to a brand new install that kept burning out the motor and nobody checked the transformer until I got there. D'oh!

[toolemanful]

Thank u guys!!! You guys are so much help for me a man fresh in the hvac world

[benitoriviera]

This is great, you don't know how much we appreciate you guys. 👍

[jasonjohnsonHVAC]

I recently did a start up on a WSHP. The heat pump is a 277v. The sparky's powered it from a 208v panel. When it came time to power up the system to test and commission it. The BMS was reporting a brownout condition. Checked my secondary xfmr voltage and wouldn't you know. Had low secondary voltage. Asked the sparky's where is my oh its in that 208v panel over there " me-" well is a 277v heat pump" got the deer in a headlights look. Of course the 460v panel next to the 208 panel was full. They ended up getting it sorted out. Always check data tag and communicate with the sparky's

[Elisummit]

Gotta love Bryan holding the camera 😂.

[johnd]

I just took over an apartment property - 275 units plus all amenities - with every air handler wired incorrectly. Tried to get my home office to get it fixed by the installer before the sale finalized and our brilliant "Director of Construction" swore up and down that there was no problem with the way they're wired.
Now they get to pay me to fix every one of these heat pumps with ECM blower motors... as well as whatever burns out before I can get them changed over.

[ddcws]

Had a commercial unit yesterday that had a failed ecm/x13 motor. High voltage to motor 208 Checked low Voltage to motor and only had 22. Transformer set at 230. Switched to 208 checked low V and had 25 now but motor still wouldn’t engage. My question is could the incorrect low voltage caused that motor to fail? I ohm’d the windings out and had 3.4 on 2 out of the 3 legs but one 1.8 on the one leg. Unit installed 2016/2017 and has been running like that 5-6 years.

[paulrozinski]

Did Bryan yell at you for losing the screw😂? Thanks fir the info. Knowledge IS power !

[michaelcostello]

Are the secondry side of transformers marked for common/live ?? When you replace them does the polarity matter

[benjamincharley]

Good morning, I bought an A/C unit for my house. My house voltage is 120/240, and the A/C unit is 208/240. Is there a way to make this A/C work for my house?

[billymcguffin]

This one drives me nuts, nobody ever changes the tap. That being said, with new Lennox RTUs, I had a call where DTE was only putting out 197v and it was tapped for 240 causing low transformer voltage and not working. I tapped to 208v and unit ran properly. The next day DTE had made their repair and the store was getting 209v and the board locked out on high control voltage

[leonardkimbler]

I have a questions about Transformer if anyone can help. So in my lab I had a 240 1ph package unit that I would rip all wires out and have students rewire the unit for experience of how to follow a wire diagram. We recently had a make over of our lab and now when I hook up this package unit, it will burn up the primary side of the transformer. My only thoughts of why this could be happening is the electrician has wired up 3ph instead of 1ph 240. Any thoughts would be appreciated. Thanks Brian for this channel, I have used many of your video's to help students understand some of the topics I go over.

[francismarotta]

Constantly find transformers that aren't set correctly on, RTUS

[LivingFearless__]

Should be how to listen to me talk for 5 minutes then how to change a transformer

[realestateservicessaleshea]

Always test first (voltage) if that truly was a commercial install and your tech didn't check voltage he shouldn't be by himself!
Time is money and callbacks waist time!
🥃🍺🍺🍺🥃🍇🏌
Stay safe.
Retired(werk'n)keyboard super tech.
Wear your safety glasses.