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It will probably run really fast before it releases the smoke.

I guess you're talking about after hours on call. I think it's reasonable to be on call. My company gives you the option of being removed from the on call list after 20 years of service. But I have...

Most RTUs have variable pitch sheaves that are suppose to be replaced with fixed sheaves after the air flow has been set. Fixed sheaves ride much better than variable pitch sheaves. I tighten the...

I think you answered your own question, the flame sensor shouldn't be coated all white. After you clean it, does the flame signal get better? Sounds like you need to setup the burner so it is firing...

My company installed a SMARDT chiller years ago for a process application. They were fairly new to the market at that time. It arrived and was completely out of refrigerant due to a factory leak in...

Older York RTUs are known for having leaks. The weather stripping around the access panels tend to leak. Hose down the unit and roof until it is leaking inside the building. Get up to the roof level...

You’re probably right about not replacing the RTRM. It just makes it difficult to do a PM without the ability to manually run the different modes of operation.

It could be damaged tubing going from the pressure sensor in the unit to the inside of the building. I had that problem one time and replaced the tubing with 3/8” tubing and it solved the problem.

[QUOTE=slctech;26644223]Possibly MSAV units? What is the full model of one of them?

Model number YCD180B4LGHB for both units.

I did try unplugging the comm cards, powered back up, but it didn’t help.

One of my customers has many Trane RTUs. I was recently doing heating PMs and found two YCD units that wouldn’t go into test mode properly. One of them went into test after several attempts, but the...

What was the actual voltage going to the motor? What was the amp draws?

I believe those burner controls require 1.8-5.0 volts. I use to work on a Trane MUA that had random pilot flame failures. I had to replace the flame rod every year. I converted it to a UV scanner and...

Good job on the repair. I repaired a frozen chilled water coil that looked a lot like that. I actually repaired it two years in a row and didn’t have to replace it until the third time it froze. This...

When you changed the combustion blower, did you make sure the screen was in place correctly? Does the burner fire smooth or rough? The manifold gas pressure should be -.20” w.c. If it has a gas valve...

Could be asbestos mud wrap. You might want to get it tested before disturbing it.

Again, it’s a concentric duct, which means the return is in the center and the supply is on all four sides. These unit are in a factory, so they just drop through the roof. The curb could probably be...

[QUOTE=heatingman;26114457]Traverse the drops, or a velocity grid the grills. Need MFG data to know true area of the openings.

Well that’s what I’m asking, how do you use a hood or traverse the...

Is there a good way to air balance or get the total CFMs of a RTU with concentric duct and diffusers?

Trane finished the controls this morning, so I did the startup after he left. I worked on the economizer fault and found that the wires had to be switched on the humidity sensor. I would have never...

Thanks for the information Slctech, I appreciate it. Trane was hired to do the controls. This is a replacement unit and the old zone sensor and communication cables are to short. My company paid...

My company just installed a Trane President RTU. The next day I found that the economizer actuator is flashing code 3, Return Air Humidity fault. The sensor has no damage and the wires are connected...

Did anyone perform a startup check? Was the air flow checked? Sounds like it may have been getting liquid back to the compressor.

It’s fine to use reclaimed refrigerant. A reclaimed refrigerant has been reprocessed using specialized machinery and tested to meet AHRI Standard 700 purity specifications. But if you just filtered...

The discharge bypass valve was replaced. Wrapped it good with wet rags and it turned out good and is functioning properly.

I have decided to replace the valve. Now I have another question, should I remove the element from the valve body before brazing in the new valve. The instructions say to wrap the valve body with a...

So I had a service call on an Ebco chiller. Found that the Sporlan ADRSE-2-0/80 Discharge Gas Bypass valve was stuck open. I backed out the adjustment screw all the way, but it was still bypassing...

I have had better luck with Nylog. I have fixed several leaks by removing the fitting, cleaning off the Leak Lock and used Nylog on the threads. I have had luck with both of them, but better luck...

[QUOTE=CHAINIK;26072960]My only bad experience was when I used Nylog for the threads of a flare fitting that went into the cover of a drier shell.

I have found many leaks around the threads on...

A few years ago I was working on a chiller. I had to replace a relief valve on the liquid receiver. I had to run a tap in the threads to clean them up, then used Nylog.

Most of the guys I have worked with don’t purge nitrogen. I do most of the time, but it has caused leaks. My company won’t pay for a purging regulator, so I have to use a regular regulator. It’s very...

If the orifices were restricted, the superheat would be high. Sounds like he has an airflow problem.

FYI, Voyager burners are not induced draft, they are forced draft/combustion blowers.

Yes, the burner plate is replaceable and if there is a flame coming out, it would be a good idea to replace it.

I have never heard of fan blade placement affecting subcooling, this is good to know. So how do you find out the proper placement of the fan blade?

Low subcooling and high discharge pressure. Probably have Non condensibles in the system and low on charge.

Sounds a little low to me if it’s a TXV system.

You suspected a failed TXV, so I’m guessing the superheat was high and the subcooling was high. Could you list the actual readings?

You should ask A-1 which part number is correct or call your local Carrier dealer. I wouldn’t trust my local Johnstone for compressor information.

Pros: Much faster, no skill needed and no flame or smoke.

Cons: No skill needed, can’t be removed, expensive and press won’t fit in tight places.

Run it through a copper coil and heat it with a torch.

Sorry about that, I was assuming it had a Maxitrol MR212D gas valve. What kind of gas valve is it? Have you checked the discharge air sensor, that could be causing the problem.

If you really have 0 vdc at the gas valve, it should be at low fire. Must be a faulty gas valve.

The thing is, with POE oils especially, if there is noncondensables in the recovery cylinder, there is also moisture in it also. I guess you can hope that the filter-dries takes care of it.

I would say United Refrigeration and Progress Supply would have it.

I’m assuming you’re talking about R-410A not R-410B. If it was recovered from the same unit, you could put it all back in. That includes the vapor. But if you’re using a recovery unit to pump it in,...

This is why we shouldn’t drink excessively before posting a question.

The Bacharach PGM-IR Portable IR Leak Detector works really good. The guys in my company that work on rack systems use it all the time. I used it one time to find a very small leak on a Process...

The filter material will break down over time. It can get small tares or holes, which will lower the differential pressure. The cardboard frames also break down and allow air to bypass the filters.

In our business, you have to work on equipment energized all the time. You can’t check voltage, amp draws or the refrigerant circuit with the power off. You just have to be very careful. That’s why...