Wrong refrigerant charge pressure gauges-High head pressure

[Cjrac]

Recently, a chiller plant we designed kept cutting out on high head pressure and were told it was a result of an incorrectly sized condesing unit. However when I looked back at site pictures from when the chiller was being charged I noticed the pressure gauge manifold had 'R410a' on it when the chiller is charged with R-134a. Can this be why the chiller keeps cutting out? Thanks.

 

[ozmosis]

Cjrac
I'm no expert (there are plenty of those in this forum) but it sounds like you may have a number of problems.
You have two refrigerants that function at different pressures, and the wrong gauge. Yes, I would say this is an issue.
Then, someone else telling you that you have an incorrectly sized condensing unit, and your company designed the chiller plant-hmm, doesn't sound good either.

Usually, before designing a chiller plant, you would consider the impact of the whole system. Usually, before switching on a newly designed chiller plant, you would check important things like gauges.
I think you need to get back to first principles.

 

[Compositepro]

Almost all gages have psi graduations as well as scales that are for the convenience of technicians that covert temperature to pressure reading for different refrigerants. So using the "wrong" gage would not cause any issue if it was used correctly.

 

[Waramanga]

Agreed, gages have different graduations and PT relations on them depending on the full scale deflection of the gage. 410 gages usualy just have that due to the high pressures making other gases not practical to indicate. Also, different oils somestimes......

 

[MintJulep]

Well, there's really not much information to go on here.

A gauge is a gauge. In and of itself no a problem. However, if the manifold set actually had been used for a refrigerant other than the correct one for the system then the charge may be contaminated with the foreign refrigerant, or a different type of oil. How much of a problem that might be depends on the total charge size.

If the system was actually charged with the wrong refrigerant, that's a problem.

High head pressure can be an indication of non-condensible gas in the system. Was the system evacuated before it was charged?

What is the cut-out pressure setting? What was the evaporator load and ambient conditions when the trips occurred?

Who told you that the condenser was sized incorrectly, and what are their qualifications? What evidence did they provide to support this claim?

You need to do more than look a pictures. Get out on site and figure out what's actually happening.