Motor protector module

[marc5180]

I was working on a Climate packaged chilled water unit today with 4 circuits that each had faults on them.
On one of the circuits i traced the fault to the compressor motor protector module.
I linked out the module whilst checking the pressures and the temp of the compressor and monitoring the amps.
The compressor ran fine and the circuit seemed to be running ok.


My first question is, can just the motor protection module be replaced? See the pic below ( the picture isnt great sorry)
http://img183.imageshack.us/img183/9150/24042008349nj5.jpg (http://imageshack.us)


My next question is, on the wiring diagram that i was following i found each circuit had aTEV bypass solonoid valve, but what is the purpose of this TEV bypass?

[monkey spanners]

Hi Marc,

That looks like a copeland scroll lecky box. Yes you can replace just the module (int69 scy?) There are different models though, one just measure the thermistors and the other also monitors the phases for reverse rotation protection.

Don't know about the solenoid though:confused:

Cheers Jon

[NoNickName]

The answer is yes for the first question. That's a INT69SC from Kriwan. Website http://www.kriwan.de or .at

I guess that the bypass for a TEV may be useful for vacuuming the circuit on suction side.

[marc5180]

Hi Marc,

That looks like a copeland scroll lecky box. Yes you can replace just the module (int69 scy?) There are different models though, one just measure the thermistors and the other also monitors the phases for reverse rotation protection.

Don't know about the solenoid though:confused:

Cheers Jon

Yes it is a Copeland scroll, like i said though i wasn't sure if it could be replaced so thanks for your helping me out.

[marc5180]

The answer is yes for the first question. That's a INT69SC from Kriwan. Website http://www.kriwan.de or .at

I guess that the bypass for a TEV may be useful for vacuuming the circuit on suction side.

Why would you need to vacuum, only the suction side?:confused:
Is it something to do with a pump down procedure?

[marc5180]

Anybody:confused::confused:

[NoNickName]

I meant to vacuum the whole circuit with just one pipe on the suction side.

[Grizzly]

Hi Marc.
Just a little further info on the INT69 Series controllers. Most of which you probaly know - but someone may benifit!
As Monkey Spanners already points out there as a large range of these controllers available.
(See link below).

A quick reset facility is available by interupting the mains supply for 5 mins.
This overides the lock out and inbuilt time delays.
For further info refer to the data sheet provided.

http://www.kriwan.com/en/Protection_and_Controls-Products--25,familyID__127.htm

This second data sheet refers to the 15 differant ptc probe temperature responce options available. (60c to 180c )

As to the TRV bypass solenoid definatly strange!!!
I have seen something similar to do with liquid injection / Oil cooling.

As you say hopfully someone can shed some light on what it is for.
Cheers Grizzly.

[TRASH101]

My next question is, on the wiring diagram that i was following i found each circuit had aTEV bypass solonoid valve, but what is the purpose of this TEV bypass?


Hi Marc

Would be interesting to see a picture of this and any other valve arrangements on this system.

[TRASH101]

Just another thought, is it a heat pump?

[marc5180]

Just another thought, is it a heat pump? No it isnt a heat pump, i see where you are going with that and that is what i thought first of all, it must be a heat pump. But it isn't

[marc5180]

I took some pictures today, not the best but i have three of them so here goes
http://img113.imageshack.us/img113/9351/25042008355sb0.jpg (http://imageshack.us)
http://img388.imageshack.us/img388/1846/25042008356lv3.jpg (http://imageshack.us)
http://img160.imageshack.us/img160/4901/25042008357nd3.jpg (http://imageshack.us)

[marc5180]

Also the LP switch factory setting is 3bar why so high?

The TEV bypass solonoid valve control relay is linked into the LP swich just before it and this also has a setting of 3bar- see attatched picture
http://img258.imageshack.us/img258/8613/25042008358ia3.jpg (http://imageshack.us)

[majo]

Hot-gass bypass is often used for multiple evaporators, or... whenever a very precise temperature is required. (+/- 0,2°C) The liquid solenoid is switched by a PID regulator, but whenever temperature reaches setpoint, the compressor would slowly reach vacuum. To avoid this, the suction pressure is kept at a certain higher point through the hotgass bypass.

What kind of cabinet is this?

[and1dude2001]

Does the bypass line go into a filter drier and then into 3 way solenoid valve arrangement? allowing pump down to occur keeping any refrigerant before the solenoid on the tev side to be held for the circuit when the Lp cuts back in, this stops the compressor from having a large short cycling time.

[marc5180]

Hot-gass bypass is often used for multiple evaporators, or... whenever a very precise temperature is required. (+/- 0,2°C) The liquid solenoid is switched by a PID regulator, but whenever temperature reaches setpoint, the compressor would slowly reach vacuum. To avoid this, the suction pressure is kept at a certain higher point through the hotgass bypass.

What kind of cabinet is this? Its a chilled water packaged unit. Hot-gas by pass is fed from the discharge line though, this looks like its on the liquid line.

[bobjob]

Hi Marc

The bypass solenoid valve pipe, does it run to another TEV onto the evaporator ?

To cover for the full duty for the compressor they may have to stage the operation of the TEVs

At full load both TEVs in operation at below 50% TEV with soleniod shuts off

regards Bobjob

[marc5180]

Hi Marc

The bypass solenoid valve pipe, does it run to another TEV onto the evaporator ?

To cover for the full duty for the compressor they may have to stage the operation of the TEVs

At full load both TEVs in operation at below 50% TEV with soleniod shuts off

regards Bobjob
Yes it does run to another TEV onto the evaporator, how does it work then because i've never come across this before.

[marc5180]

and why would the pressure switch be set at 3 bar? the same as the Lp switch?

[marc5180]

Also if it was as you say then why would the solonoid be called TEV bypass solonoid becase it isn't bypassing it?

[bobjob]

Hi Marc

Many of those Climate chillers were built in the factory to a clients spec.

They would normally use there Hitachi chillers for standard work but if the customer required such things as low noise operation or low water flows,low temperature operation they would modify a Hitachi chiller or build something from scratch.

The 2 TEVs may by used with the unloading

The setting of the pressure switch should be above the LP cut out to unload the cylinders and close off the refrigerant going to the one TEV

from your information do you have 4 circuits or do you have 4 compressors ?

If its 4 compressors with only 2 refrigerant circuits, this would be a standard Climate chiller the pressure switch would probably switch off the one TEV and one of the compressors.

regards Bob

[airefresco]

My dad used to work for Climate and I asked him about this. He gave the exact same answer as Bob. So, I would go with what Bob said.

[Inverter man]

Marc,
the TEV bypass is for low ambient conditions. It is energized for the 1st 30 secs after compressor start up to prevent the suction pressure dropping too low to cut out on LP and preventing the evaporator temp from dropping too low, thus giving the head pressure time to rise to a satisfactorily suitable level and hence raise the suction pressure.
Hope this helps.