The first thing I do when an rtu is running mechanical cooling in cold weather is ohm out the outdoor air sensor. 9 times out of 10 that's the problem.

Working on my company's equipment. If you ever want to confirm the heater is working on those MUA units stick a temp sensor in the same spot as the discharge air sensor. Then activate heat and pull the #4 wire off the amplifier. That forces it into high fire. Adjust the gas on the main valve so you're getting roughly 70 degrees TD. Then put the #4 wire back and pull the #5 wire which forces it into low fire. The modulating valve has a blue cap on the side where you adjust low fire trying to achieve 10-13 TD. Once you got that put the #5 wire back and adjust the amplifier to a temp and give it a minute or two and see if you're reading within a few degrees of what you set it to. Sometimes the discharge air sensors go bad so it makes them over or under fire by a lot.

Impressive troubleshooting

Rule of thumb is 10% extra to go from 230 to 208

Master built. Great content!

Here in Houston, lots of the restaurants have the A/C going even when it's in the 50's outside. I've been shivering in the front while waiting for the food. In one case, I helped the manager get the thermostat control switched to heat mode - someone'd been buggering the buttons. I ended up popping the cover off of the white/rogers switch, setting the switches and buttons back in place (broken loose), and seating the case back on. Then they could use the buttons and levers.

Rick, your content is amazing ! Thank you for sharing !

You need to look for service facto ( SF) on the name plate to know how to set overload over FLA.

Another great video! And the place will save a little energy by not running the air conditioner for the kitchen when it is 19F outside! Reminds me of a call I got one night, while I was at a concert, the back up on call guy was pretty new, it was 50F outside, and he had a call for a computer server room fed by a 3 ton rooftop Carrier unit. I told him to take off the air filter cover, so it would take in about 50% outside air. He asked "Why". (he was very new). On Monday, I installed a fan cycling switch so the head pressure would stay high enough to not trip the unit on low suction pressure. I have found freezers with two fans, and nothing to shut off one of the fans when below 55F outside!

thanks for your password 😂😂😂

Hell yeah! It's MUA season, I got one coming soon. Nice job Rick,

T-series thermostats are horrible. A Pro 8000 would be better. I agree with changing to a Jade controller.

19 degree's really ? My wife runs about 15 -16 degrees ... Uh Oh I gotta go I think she's pulling into the garage 😂😅🤣 Good vid as usual ...

Upgrading to the JADE would get 2 new sensors, ordering the kit, and that may be in stock rather than just the sensor. As you stated, the JADE would make things much better. For some reason I did not think the new sensors worked on the old controls. It has been awhile since I dealt with one, though.

Sadly from my experience on those Fluke 900 series clamp meters, they do not do well over 2k Ohms of resistance. I find myself thinking a 10K Honeywell TR21 is bad because mine is not reading any resistance. But I double check it with my 17B in the truck and I suddenly have resistance.

Those crappy sightglasses! I take and remove it, replace it with 4x4 box cover. Cover easily removes for future service, super cheap.

On dual belt applications, I always find one belt just slightly looser than the other. Drives me crazy. They never seem to wear evenly.

Anything you say I will quote LOL! You are doing a great job would you please try to keep your little self warm. I know it is impossible I hope people appreciate what you do! I know we have maintenance in the building I live in now they get on the roof they take care of our heating and our whole entire building. And I make sure and tip them on a regular basis. You know oddly enough if I ask for something they're here in about 30 seconds. I appreciate them tremendously. I never realized I've lived in a retirement condominium! But these people are a blessing! And people ought to understand you are a blessing!

I've never worked on a allied or even heard of them, but I know with carrier I believe it is you economize it is stage 1 in the winter and then stage two cooling would bring in compressor one and then if all else fails and it can still not reduce the temperature it closes the economizer and brings on stage two therefore you running full cooling

I've replaced a few of those enthalpy controls.. Wasn't taking the biscuits to the baker .lol

19 😮

Good job Rick.

you may be better off with a resistor decade box, with label printed stuck to it for the settings. then again that may be too much fiddle farting around, but it would be widely selectable for the unknown junk you have to look up or call tech support on. then again, maybe just bypass all that useless junktronics crap with simple controls and let them deal with burnt out large components. "danged if you do danged if you don't" lol

Nice video Rick

19 Degree’s! Hope that’s Celsius😀- Good video / stay Warm Rick 🥶

You do know. Thermistors where first used. Back in the 60s. They determined to be unreliable. Because they fail in just a few years. Unlike the mechanical controls that sometimes outlasted the equipment. Then all of a sudden in the 80s. They where brought back in as new technology. There are chain stores we service. All newer YORK. I carried spare sensors. Always can find at least one that is bad on one of the units. I said the same thing you did. Needs new sensors. I would replace all of them. They are cheap and all the same age. Thermistors go bad overtime.

I wonder what it is with Fluke clamp meters and resistance ranges. They top out at 60K on the better meters like yours. Some are as low as 4K. While my Extech is a cheap meter compared to a Fluke, it will measure up to 40M according to the spec sheet. Accuracy at that end, who knows?

Ha Rick did you make a video on your jumper box

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Ruff and Warsh 😂

Are you starting to see any Commercial VRF units installed?

👍👍 Nice job 👍 👍

I'm thinking about laser eye surgery, is it worth it? I can't see shit from 10 meters onward, close up its fine.

347 thumbs up

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