lights dim when a/c goes on, hart start question

[heetseeker]

I have two questions

I recently had a new a/c installed. It seems that when the a/c kicks in my lights dim for a second. This did not happen with the old system. The new system has a scroll type compressor and the old one did not. Do scroll compressors require more current? Is this common for the lights to flicker on start up? Current system is:
AUD120R9V5k4
Allegiance 12 2A7A2048A1000A
TXC050C4HPDO #83 orifice




The installer put in a coil without a txv by mistake and will be putting in a new coil that has one. I think it is A/S TXC065C5. The tech rep at the distributor says a start kit is recommended. What problems would I look for if the installer does not put in the start kit. Does a start kit put more or less strain on a system?

Thanks for your replies.

[Mr Bill]

Originally posted by heetseeker

I recently had a new a/c installed. It seems that when the a/c kicks in my lights dim for a second.


The installer put in a coil without a txv by mistake and will be putting in a new coil that has one.

Well if there dimming with a piston they will be going out for a day with a txv.

[on call]

Hard-Start kits increase the starting torque of the compressor by putting more capacitance in parallel with the capacitor of a PSC motor during start-up only. More torque means more strain on the motor. The kits are used to compensate for low voltage or high starting loads.

I would check the voltage on the compressor between the C-R posts during the start to see how low it is dropping. The mfg. will have a low value; typically about 10%.

The TXV will increase the starting torque required if the pressures on the low and high sides of the TXV don't equalize enough before the compressor starts again.

Since the scroll has no valves like the recip compressor, I believe that it should equalize the pressures even if the TXV won't in enough time before the next start. If not, a delay should be used to prevent this.

I would also make sure that there are no other problems causing the higher load (like overcharge). You might be covering up another problem that might eventually cause system damage if not corrected.

[Edited by on call on 11-12-2005 at 03:18 PM]

[dugfish]

Have tech put hard start kit on it wont hurt anything easiest way to explain it is that it starts the motor quicker. If your coil has a non bleed TXV on it you will need the hard start kit.

[The Penguin]

same thing is happening in my home (just installed a hp) I was told years ago it depends upon how far you are from the pole transformer that has the most effect upon this.

I intend in putting a time delay relay on the relay for the indoor fan for 5 secs to allow the can to start then the fan motor(belt drive oil furnace)

[bluetooth751]

The problem you are speaking of is very common. Scroll compressors are famouse for dimming lights.

Make sure Hard start kit is installed with TXV on coil.
Supply wire and circuit breaker disconnect is the correct size.
All line connections are tight
Line voltage is good.
Refrigerant charge and compressor amps are good.

Even if all the above is good you will probably still have the same problem. You should then consult you energy provider. More than likely you will just have to live with it.

[heetseeker]

Thanks for the replies, they were helpful. I asked my installer if scroll compressors caused lights to dim and he said no, that it probably was something to to do with the power supply. Have others had bluetooth's experience that dimming of lights is common with scroll compressors?
Is adding a hard start kit a complex job? I am asking since I am not sure how experienced my installer is in adding a hard start kit.

[toyo066]

THe hardstart is not hard at all. You have to first determine which one you need. TO5 or the KS1 T05 is for units 3 ton or less... KS1 is for any thing from 3.5 to 5 ton. you have two wires and you put one on the HERM side of the capacitor and then one on the COMMON side. That is it. I would check your breaker side to see if it matches the Cond. could be pulling more then what your breaker is up for... Hardstart is a good thing anyway to add to your unit for your compressor's life.

[bluetooth751]

Originally posted by heetseeker
Thanks for the replies, they were helpful. I asked my installer if scroll compressors caused lights to dim and he said no, that it probably was something to to do with the power supply. Have others had bluetooth's experience that dimming of lights is common with scroll compressors?
Is adding a hard start kit a complex job? I am asking since I am not sure how experienced my installer is in adding a hard start kit.

No adding a hard start is not a difficult job, but a hard start is expensive.

I was told that too many homes powered by one transformer will cause this problem.

Ask more of your neighbors if they experience similar problems.

[t527ed]

i have been installing scroll compressors with expansion valves since the scroll was introduced (1990??). i have NEVER had to install a hard start kit. look elsewere for your problem.

[addfreon]

Nah...a simple Supco SPP6 super boost should do the trick....