5-2-1 Compressor Saver - Which size?

[chikoo]

Few things to note:
1. The outdoor unit is about 5 feet from my electric panel. The panel is inside the garage, the unit outside. So that should address the distance question.
2. The units are 8 years old. Never had any issues till yesterday. The contractor introduced the 5-2-1 CSRU3 and the unit fired up promptly. Does this rule out the voltage issues that could have been due to the electrical wiring? or is this simply masking it? or was it simply a bad thermistor?
3. I have not noticed any electrical fluctuations in the house, and I have quite a few computers running 24x7. They would surely have been affected I imagine.

Thanks for the 5-2-1 part# vstech. I am now trying to determine if I should ask for the Carrier Hard Start Kit KSAHS1501AAA or the 5-2-1.

thanks!

[chikoo]

The damage would happen in the first partial second when it starts. A compressor will create a specific back EMF when starting, the relay needs to match the pick-up voltage and the drop out voltage of the compressor.

It may start 20/30 or fifty times before failing, each time it starts and the relay does not drop out the start winding will overheat.
The best thing to do is use the hard start kit from the manufacturer that matches the compressor in your unit, actually the best option would be to correct the starting problem which may be low voltage.

Well if it's been running for 2 hrs, the start assist has not had any effect for 1 hr 59 minutes and 59.5 seconds, it only helps start the compressor, has absolutely no effect on running the compressor.

Found this on the 5-2-1 website FAQ. does this mean it is OK to leave the CSRU3 in place?

With the third wire the potential relay on the 5-2-1 can read true back-emf. This means the device can accurately determine when it should go out of circuit. Other products with two wires are either operating on a timer and are not equipped to read true back-emf, which means that they be in circuit too long or not long enough.

[Mr Bill]

Does this rule out the voltage issues that could have been due to the electrical wiring? or is this simply masking it?.

No, It "could" be either one, if your concerned about the possibility of it being an electrical issue, you might call out an electrician to check out the electrical, from the panel to the unit.

[vstech]

Found this on the 5-2-1 website FAQ. does this mean it is OK to leave the CSRU3 in place?

With the third wire the potential relay on the 5-2-1 can read true back-emf. This means the device can accurately determine when it should go out of circuit. Other products with two wires are either operating on a timer and are not equipped to read true back-emf, which means that they be in circuit too long or not long enough.

... no.

[Mr Bill]

Found this on the 5-2-1 website FAQ. does this mean it is OK to leave the CSRU3 in place?

No, this is the one you can leave in place, the CSRU1 5-2-1 (for 1.5 -3 TONS). If you had a service co. install the wrong one, just call them up and tell them you want the right one, before they get to buy you a new unit for installing the wrong one. If you did not install this yourself, just call them up and tell them what you found out, there should be no issues, well unless of course you bought these and installed them.

[chikoo]

So I went ahead and asked the question I had to 5-2-1 themselves and this is their response.

Typically our CSRU2 would be used on a 3 ton unit, but sometimes it can be necessary for a U3 in this situation. I have copied our technical director on the email to provide further insight.

I also called up my contractor and he very confidently responded that the compressor was really struggling and therefore he went with a larger capacitor to provide the extra push.

[second opinion]

So I went ahead and asked the question I had to 5-2-1 themselves and this is their response.



I also called up my contractor and he very confidently responded that the compressor was really struggling and therefore he went with a larger capacitor to provide the extra push.

If that was the response of you contractor and the mfg's support they truly have no knowledge of what criteria is required for start components for a compressor.

[Six]

Whats the difference in microfarads from the CSR 2 to the CSR 3 ?

I wouldnt lose sleep over it.

[chuckcrj]

Whats the difference in microfarads from the CSR 2 to the CSR 3 ?

I wouldnt lose sleep over it.

Microfarads is not the main reason to install the correct start kit.

It's even more important for the potential relay to be correct.

[timebuilder]

Microfarads is not the main reason to install the correct start kit.

It's even more important for the potential relay to be correct.

Yes. The relay is the important part.

I would expect the correct 5-2-1 to start the unit just fine.

[Six]

Microfarads is not the main reason to install the correct start kit.

It's even more important for the potential relay to be correct.

I have a couple of 521s in my truck. I cant see the coil voltages on their potential relays.

To make a statement like the one above wouldn't you at least need to know what the pickup and dropout voltages were ?

And lets assume the compressor couldn't maintain the reverse EMF to keep the potential relay energized and it drops the start cap into the circuit.

The start cap will go before the compressor winding. They're not rated for continuous duty.

[chikoo]

The Plot Thickens

The AC outdoor unit is a Carrier Model Number: 38BRC036 (installed mid 2004)
From what I gather on the Sears Parts website, this model contains a scroll compressor.

Does the scroll compressor benefit from the 5-2-1 hard start kit?

Btw, this is day 8 with the 5-2-1 kit installed on this unit and it is firing up fine and keeping the house cooler than ever before.

[second opinion]

The Plot Thickens

The AC outdoor unit is a Carrier Model Number: 38BRC036 (installed mid 2004)
From what I gather on the Sears Parts website, this model contains a scroll compressor.

Does the scroll compressor benefit from the 5-2-1 hard start kit?

Btw, this is day 8 with the 5-2-1 kit installed on this unit and it is firing up fine and keeping the house cooler than ever before.

Well since the scroll starts unloaded the theory of the pressures equalizing due to the TXV just went out the window.