True roll in cooler, new condensing unit. Compressor not starting everytime

[UmmScott]

This single door true Roll in cooler has had numerous compressor changes from another company and cap tube replacements.
Owner wanted problem fixed permanently and gone.

I quoted to replace condensing unit, flush evap and go with a TXV instead.
Replaced the 134a and crap tube with new condensing unit with receiver... an AE4440Z-AA1AGB, and 1/4 ton danfoss TUA TXV valve.

Works and cools great, superheat at compressor is 23F. Problem...
The AE4440Z has trouble restarting sometimes after the off cycle. (Off cycle is usually 8 to 10 mins) compressor pops overload.
Usually after the 3rd attempt it fires right up with no issue.
Start cap is good at 300uf and well within range.
Pulls current, 10a thru start cap when trying to start.
Checked for voltage drop, there is 5 volt drop from 120 to 115V when attempting to start...

Very weird.. I'm ordering new starting components under warranty anyhow but.
What do you guys think?
It should start everytime, its a high start torque model with the 1st 4 in the model #.

Any ideas?



Sent from my SM-N920V using Tapatalk

[crazzycajun]

How are the points on the tstat

[shellkamp]

You could install a LL solenoid and make it a pump down system - that will make starting easier on the compressor.

Sent from my SCH-I545 using Tapatalk

[shellkamp]

Is the TUA valve a hard shut off?

Sent from my SCH-I545 using Tapatalk

[UmmScott]

How are the points on the tstat

A12 700 was installed with the condensing unit

Sent from my SM-N920V using Tapatalk

[UmmScott]

Is the TUA valve a hard shut off?

Sent from my SCH-I545 using Tapatalk

No sir, I have used this valve on many other applications.

Ive used it on an old r12 reach in that was controlled thru low pressure and it worked fine.

Sent from my SM-N920V using Tapatalk

[shellkamp]

No sir, I have used this valve on many other applications.

Ive used it on an old r12 reach in that was controlled thru low pressure and it worked fine.

Sent from my SM-N920V using Tapatalk

Yeah, I know, it SHOULD work fine; but it doesn't, does it? :grin:

My gut tells me a pump down solenoid or hard shut off valve would solve this problem for sure. There may be some migration going on



Sent from my SCH-I545 using Tapatalk

[Poodle Head Mikey]

Are you controlling on a constant cut-in stat? That YOU KNOW for a true-fact is a constant cut-in thermostat?

PHM
--------

This single door true Roll in cooler has had numerous compressor changes from another company and cap tube replacements.
Owner wanted problem fixed permanently and gone.

I quoted to replace condensing unit, flush evap and go with a TXV instead.
Replaced the 134a and crap tube with new condensing unit with receiver... an AE4440Z-AA1AGB, and 1/4 ton danfoss TUA TXV valve.

Works and cools great, superheat at compressor is 23F. Problem...
The AE4440Z has trouble restarting sometimes after the off cycle. (Off cycle is usually 8 to 10 mins) compressor pops overload.
Usually after the 3rd attempt it fires right up with no issue.
Start cap is good at 300uf and well within range.
Pulls current, 10a thru start cap when trying to start.
Checked for voltage drop, there is 5 volt drop from 120 to 115V when attempting to start...

Very weird.. I'm ordering new starting components under warranty anyhow but.
What do you guys think?
It should start everytime, its a high start torque model with the 1st 4 in the model #.

Any ideas?



Sent from my SM-N920V using Tapatalk

[UmmScott]

Yeah, I know, it SHOULD work fine; but it doesn't, does it? :grin:

My gut tells me a pump down solenoid or hard shut off valve would solve this problem for sure. There may be some migration going on



Sent from my SCH-I545 using Tapatalk

Wait...sorry i think i misunderstood.
Yes, it is a hard shut off. It does Not have a bleed port or anything inside it.

Thats what i meant to say.

And PHM yes its an a12 700.

Sent from my SM-N920V using Tapatalk

[shellkamp]

Are you controlling on a constant cut-in stat? That YOU KNOW for a true-fact is a constant cut-in thermostat?

PHM
--------

Alright; where are you going with this?

The only way I could relate this issue to thermostat type would be a too-short of an off-cycle.

Sent from my SCH-I545 using Tapatalk

[UmmScott]

Alright; where are you going with this?

The only way I could relate this issue to thermostat type would be a too-short of an off-cycle.

Sent from my SCH-I545 using Tapatalk

The off cycle is around 10 mins usually with an empty box.
Thats plenty of off time in my opinion.

Plus...if i unplug/plug in...unplug/plug in a few times every 5 seconds...
Theres times when it will start and theres times when it won't

Sent from my SM-N920V using Tapatalk

[shellkamp]

The off cycle is around 10 mins usually with an empty box.
Thats plenty of off time in my opinion.

Plus...if i unplug/plug in...unplug/plug in a few times every 5 seconds...
Theres times when it will start and theres times when it won't

Sent from my SM-N920V using Tapatalk

Then I'd be looking solely at the starting components

Sent from my SCH-I545 using Tapatalk

[itsiceman]

No concerns with that head?
Compressor must be starting back up after it cools off a little more.

[WT70]

I'll never understand the fascination with 404 as a Med Temp refrigerant as a conversion anymore. But anyway.

What's the pressures when trying to start? Equalized? Does it always do it on short cycle or will it do it after sitting a while too? As said before, contacts on temp control ok?

Sounds more like either a voltage or starting against pressure.

295? That's what. 115 SCT?

May be a big part of your issue. Things get hot, they get a little tight, a little harder to start? Cool off starts right up?

Hrm. Ok. You converted. I don't see a receiver. Is that a receiver/drier?

I'm wondering if you removed a little refrigerant, which will raise superheat, cause you to open valve to lower superheat and all that will lower discharge.

What's subcooling?







Sent from my iPhone using Tapatalk

[shellkamp]

I'll never understand the fascination with 404 as a Med Temp refrigerant as a conversion anymore. But anyway.

What's the pressures when trying to start? Equalized? Does it always do it on short cycle or will it do it after sitting a while too? As said before, contacts on temp control ok?

Sounds more like either a voltage or starting against pressure.

295? That's what. 115 SCT?

May be a big part of your issue. Things get hot, they get a little tight, a little harder to start? Cool off starts right up?

Hrm. Ok. You converted. I don't see a receiver. Is that a receiver/drier?

I'm wondering if you removed a little refrigerant, which will raise superheat, cause you to open valve to lower superheat and all that will lower discharge.

What's subcooling?







Sent from my iPhone using Tapatalk

How will removing refrigerant help? He has a reciever.

Sent from my SCH-I545 using Tapatalk

[pecmsg]

With out a pump down it is possible your getting liquid slugging

[WT70]

How will removing refrigerant help? He has a reciever.

Sent from my SCH-I545 using Tapatalk

I just stated "I don't see a receiver,Is that a receiver drier?"

So.

Still can be overcharged with a receiver.


Sent from my iPhone using Tapatalk

[UmmScott]

I just stated "I don't see a receiver,Is that a receiver drier?"

So.

Still can be overcharged with a receiver.


Sent from my iPhone using Tapatalk

Only put in 1Lbs 4 oz.

Pumpdown capacity is 2.5lbs.


Its 85F in the room kinda warm yes.
Pretty sure this is starting components. Everything else checks out ok.

Sent from my SM-N920V using Tapatalk

[PaulServiceTech]

That head looks a bit high to me. I don't know the ambient however


Sent from my iPhone using Tapatalk

[UmmScott]

Sooo...

If mine cant start with a little high head pressure..

Then how does every other unit out there with dirty coils start fine?

Sent from my SM-N920V using Tapatalk