Replacing Bad Compressor

http://www.rapidtables.com/convert/power/ton-to-btu.htm

Yes if the 10T unit has two compressors and both of the 72000 BTU compressors are the same voltage and both are designed to handle the same refrigerant type as the 10T compressors.

However, the power usage will be somewhat higher when the system is running and may increase your power bill.

Depending on system design the length of compressor run time may be shortened enough to offset the higher usage of power.

my point is if i use the two new 72000btu compressor i will get 12 ton but the unit size is 10 ton , so is that ok nothing will be wrong in refrigeration system or i have to use two 5 ton (60000btu)

It depends how the system is controlled. Maybe there are standard control schemes which some posters are aware of, but I'm not. If the compressors can operate at reduced output, or intermittently, you could be OK. Can't tell from here.

The compressor(s) will cycle on and off based on the temperature control requirement, suction pressure, and discharge pressure which is monitored by instrumentation external and independent of the compressor.

Using a larger capacity compressor will not change the operating parameters as such so the pressure and temperature cycle of the larger units will be the same as the smaller ones.

It will not make any difference to the operation other than energy consumption and possibly shorter compressor on-off cycles as long as the compressors are compatible to the type of refrigerant being used in the system.

You will encounter difficulty in matching the mounting of the larger compressors in the existing location due to larger physical size. If you have water cooled compressors the existing cooling system may not be adequate and if so, the operating temperature will be higher.

You must verify the electrical supply and controls are adequate in size to handle the increased load. If they are not adequate, all must be changed out to the correct size.

If all existing electrical equipment is adequate, then the current and voltage protection trip circuits must be adjusted to meet the larger compressor requirements. This will include adjusting the overload relay settings or changing the O.L. heaters out if the system is older. This will also require making sure the added inrush current is accounted for in the protection relay(s) if so equipped.

Be very attentive to the larger compressor crankcase heaters and make sure the electrical supply and temperature controls can handle the added current load.

If the guy doing the install knows what he is doing during the systems refill it shouldn't be a problem.

He should be able to tweak the refrigerant charge a bit if overcooling and freezing up the evaporator units becomes a problem but more than likely running a bit of extra compressor capacity wont bother the overall system to any great degree.

At worst you may want to put a start delay on one compressor so that when the system powers up both compressors are not starting exactly at the same time. A 1 - 2 second delay should be more than enough.

you need to hire a professional HVAC TECH, you're clueless on this project to the point of being dangerous

You received good answers from everyone here so far. If I was doing this, I would follow everyone's advice, But I would also install a sight glass at the condenser inlet for cross reference to the your manifold gauges, due to the fact that you now have change the refrigerant charge listed on the data plate and overdriving the system with the larger compressors.

that isn't where a sight glass belongs

Aww, come on, sight glasses belong everywhere.

The J.M. Perry Trade Institute in Yakima, WA, USA, has a demo refrigeration system built all with blown glass, except for the compressor. Pretty educational.

This is not a good idea.....you can go up a few thousand btu's , but a full ton will not work properly for many reasons....

The best advice will be found always from the original equipment manufacturer, as will the correct selection of warranty-compatible spare parts.

So the best course of action would be to speak to York directly by telephone. Do turn off All Caps first, though, lest York infers a SHOUTING POTENTIAL CUSTOMER, and fails to respond because of it.

you've gotten some poor advice....your coils wont match your compressors nor will they be properly circuited.

Bristol Compressors :: Installation and Service Instructions

Bristol compressors are completely interchangeable with other manufacturers. However, electrical specifications, tubing configurations and wiring connections may vary. Before installing and starting a Bristol compressor, you must review the wiring diagrams and check for correct electrical components.

Compressor Cross Reference

An air conditioning or refrigeration system is carefully designed for best efficiency.

This includes sizing of compressor,evap and condenser coils.

Change any one component,and you will affect overall efficiency of the system.

No,you cannot get a higher BTU system by simply installing larger compressors.

The expansion valve controls the amount of refrigerant going into the evap coil.

Too little,and you lose cooling ability,too much,and you risk slugging the compressor with liquid refrigerant ,which could ruin the compressor valves.

Too much liquid refrigerant can also cause scrubbing of the oil from vital parts of the compressor,resulting in compressor failure.

A little,and I do mean a "little" liquid exiting the evap coil is not bad, and allows for a variation in load.

And there are ways of handling this and preventing it from getting to the compressor,using properly sized accumulators.

Scroll type compressors are more tolerant to slugging than the standard type reed-valve compressors,but it will also shorten their life span.

You must be able to measure and calculate the superheat,sub cooling,head pressure,suction pressure and refer to a pressure/temperature chart to get it right.

IF you are not familiar with these terms or procedures,stop where you are.

Don't do anything.Call a certified AC technician to do the job.

You will save money in the long run,and not have so much scrapped equipment to get rid of and explain.And you can keep you present job.

I will run with Shockhiscan #1 and #10 for detail.

But as you say you will end up with a 12 ton unit, and are you likely to use the extra 20%?

Because if so, everything else: - nuts bolts pipes cables starters breakers valves power water etc, will have to cope with a 20% extra load, that could then become normal, added to which everything would then have to cope with additional load in fault conditions.

Your extra cooling could make things hotter!

On balance the use of a 20% bigger unit is certainly a possibility and worth investigating.

HiTekRedNek #17

I note what you say and I disagree with you. He might get a 12 ton unit. The chiller/condenser system might be big enough. An investigation of the system, as recommended, will reveal that.

For we all we know he might not have had a well designed unit to start with. That's why his compressors have gone 'bad'.

My assumption he might get a 12 ton unit is perfectly valid, and whilst it might turn out you are right, launching an attack on me at this stage is a bit premature.

I was not attacking you at all.

If I had been there would have been no doubt about it.

Usually what takes a compressor out is either a lightning induced power surge or direct hit,or lack of lubrication.

Lack of lubrication can be caused by a evaporator that is too small,or severely clogged.

The liquid getting into the suction side of the compressor can damage the valves and wash out the lubricant from the moving parts,causing a compressor lock up.

Another cause of compressor failure is high head pressure,caused by

non-condensibles,like air,for instance,and a clogged expansion valve, or a dirty

condenser coil or too much refrigerant.

If the compressors are the original ones,you can bet that they were not mis-matched from the factory.

The installers may not have purged the system properly,allowing moisture or air to remain in the system.

How many systems have you ever installed or maintained?

How much experience do you have in servicing A/C systems?

Not an attack,no offense intended,just a couple of questions to judge from whence you speak.

No reply to my questions,Horace?

Perhaps you are a philosophunculist.(Google it if you don't know the definition.)

If the definition does not fit,then simply ignore it.

No harm intended or done.

If on the other hand it causes pain, then the point is proven.

CAUTION:

This may be interpreted or construed by some supercilious, or super-sensitive

individuals as an attack, but it is not.

It is merely an attempt to qualify a given answer to a previous question. (#18)

Andy, is that you?

No.This is Kingfish.

Holy Mackerel!

Oh, the political incorrectness of it all!

Don't listen to these other guys, you can use these compressors!

Before installing and starting a Bristol compressor, you must review the wiring diagrams and check for correct electrical components.