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dear.mr.davidov
22-03-2008, 05:39 PM
Hi all
i have problem with exv carrier. I fill that EXV don't open (LP 30psi, HP150psi, InWater 20C) but don't no how to check it maybe controller doing this problem. EXV have 5 wires from controller board grn,blk,wht,brn,red how can i check them. EXV 1500 steps 12VDC.

Brian_UK
22-03-2008, 06:07 PM
Welcome to the forum.

Do you have access to the chiller by computer which will enable reading of the sensors and EXV?

Also, which model/year is the machine?

Airmechanical
22-03-2008, 08:30 PM
i have found on carrier gt series chillers with EXV's that the stepper motor

always either works or it does not, that being said i have taken apart many

EXV assemblies and always seem to find an excess amount of debris on

and around the piston, which causes piston to drag slowly which also

causes nuisance safety lockouts, i have cleaned up a couple pistons

and lightly steel wooled the cylinder and it has fixed the problem

pump down the circuit and pull the valve apart you will see what i mean



.

D.Evans
22-03-2008, 08:31 PM
I think the valve you are talking about is a stepper valve which often has two pairs of cables. One pair for opening the valve and one pair for closing the valve. I suspect the green cable is the earth cable. The driver would indicate by two LED's the valve opening or closing. You would need access via a laptop to see the actual settings if they are not available from the machine.
You don't say what the refrigerant is in the system but are you sure that the system has a correct charge? An indication of a shortage of charge would be the opening LED would always be lit as the valve tries to achieve a pre determined superheat value normally between 5 and 8 degrees K.

dear.mr.davidov
22-03-2008, 08:54 PM
I donn't have acsses to the chiller by computer. I has checked EXV sensors they alright. I suspect that EXV motor don't receive comand to open. I want to gauge with voltmeter exits from controller to EXV. But i don't know what signal he must receive (0-10vdc or 0-20mla) and what mean each color of wires.
The chiller 30GT040 Flotronic year i don't know i think 1990 but i not sure

dear.mr.davidov
22-03-2008, 09:11 PM
I had taken apart EXV and don't find any debris.
Refrigerant in the system R-22 i'm sure that system has not corect charge, but i can't doing anything now EXV don't work properly. before replace it i must be sure that repair it's impossible

Airmechanical
22-03-2008, 09:22 PM
I had taken apart EXV and don't find any debris.
Refrigerant in the system R-22 i'm sure that system has not corect charge, but i can't doing anything now EXV don't work properly. before replace it i must be sure that repair it's impossible


is it only 1 stage

can you take the plug off 1 and put it on the other circuit

or is it only single stage?

i have had to replace a few stepper motor drives

fortunately i always had additional stages to test faulty components



.

roger the chill
23-03-2008, 01:09 AM
If L.E.D.s on drive card flashing try changing cable first is cheper than new valve

dear.mr.davidov
23-03-2008, 06:33 AM
i was changing cabelim betweeng circuits this is not solved my problem.

nike123
23-03-2008, 08:21 AM
What is manufacturer and model no. of that EEV?

dear.mr.davidov
23-03-2008, 02:19 PM
maybe anyone know where i can get the EXV's schema

nike123
23-03-2008, 02:38 PM
If you provide us with data I asked above, maybe we could.

oldschooleng
12-07-2009, 09:17 PM
set your test meter to vdc.turn the chiller off/on.the red wire is common between the red and all the other wires the voltage should fluctuate between 0-10v if you have no voltage or fixed voltage the driver is faulty.if the cable is good check the valve it should be about 23 ohms equally on all pins or the piston is stuck

goshen
17-07-2009, 02:49 PM
hi welcome aboard we have had to change many of these exv the carrier manual has a step by step guide how to check these valves u could probably get by by changing only the internal part of the valve but carrier only sells the entire exv so good luck

serviceman
12-11-2009, 08:04 PM
see wing prube component developer's manual gives steps through seguir.o removed the gas system and desesambla the exv and pruebala.

Gary
12-11-2009, 08:32 PM
Refrigerant in the system R-22 i'm sure that system has not corect charge

The EXV controls the flow of liquid refrigerant into the evaporator. If the system doesn't have enough refrigerant, then there is no liquid for the EXV to control.

james10
02-04-2010, 11:46 AM
set your test meter to vdc.turn the chiller off/on.the red wire is common between the red and all the other wires the voltage should fluctuate between 0-10v if you have no voltage or fixed voltage the driver is faulty.if the cable is good check the valve it should be about 23 ohms equally on all pins or the piston is stuck
you'll find it's 25ohms +/- 2 between red wire and the others

moideen
02-04-2010, 05:03 PM
Hi all
i have problem with exv carrier. I fill that EXV don't open (LP 30psi, HP150psi, InWater 20C) but don't no how to check it maybe controller doing this problem. EXV have 5 wires from controller board grn,blk,wht,brn,red how can i check them. EXV 1500 steps 12VDC.

Check the resistance red wire to others. Should be get 25+ /-.if resistance is ok,check the cooler suction temperature sensor, compressor gas temperature sensor, expansion board(using for 30 gh and gtn model).if all are ok, pump down the system and remove the motor assembly. This stepper motor using ball bearing. may be due to the defect of bearing motor will not work. You can replace the bearing.
Moideen-dubai