[dmarkh]

I'm in the process of adding a hard start kit to my unit for the sole purpose of helping my generator start my unit. The unit is a 3.5 ton American Standard #2a7a5042a1999aa. The unit is 10 years old and works great. It's just that when on generator power, 1 out of 10 times, the unit will not start. 15-20 seconds later it tries again and always seems to start on the second attempt. I've hooked an AMP clamp to the unit and I get around 50-55 max amp startup surge. Then draws 11-12 amps while running. My generator is a 40 amp max unit. The generator head is an ST10. My installer (now retired) says a hard start kit would probably cure the problem. However, when he attempted to order an OEM unit for me, he was told they never made one for that unit. So he told me to go ahead and get one of those 5-2-1 kits. I got the CSR-U2 model. When I went to install it, I noticed some paper work in an envelope inside the unit. I guess I/we should have looked at that first because it specifically calls out a start kit #BAYKSKT260. And sure enough they are available.

My question is, will the 5-2-1 kit function properly without damaging my unit, or should I really go ahead and get the OEM kit? My installer says he installs the 5-2-1 and kick-starts all the time and rarely bothers with the OEM units. I want this unit to last another 10 years so I thought I would ask the pros.

I don't mind spending the extra money for the OEM kit but if I don't have to... you know...

Thanks
Mark

 

[pecmsg]

For that unit to work you should have a generator capable of handling the high inrush current required. As your #'s said 50 - 55 amps inrush on a generator designed for 40 amp output. (BTW the actual inrush is much higher then your meter is reading) You may damage both pieces of equipment.

What else are you trying to run on the gen at the same time?

How long is the A/C off before attempting a start?

 

[dmarkh]

For that unit to work you should have a generator capable of handling the high inrush current required. As your #'s said 50 - 55 amps inrush on a generator designed for 40 amp output. (BTW the actual inrush is much higher then your meter is reading) You may damage both pieces of equipment.

What else are you trying to run on the gen at the same time?



How long is the A/C off before attempting a start?

I generally will be running the refrigerator, a small deep freeze and maybe some lights. This is an emergency backup generator used for, well you know, an emergency. Obviously the outside temp determines how long the unit is off between the cycles and my thermostat is one of those fancy ones. It won't allow quick cycles. There is always some delay. In any case on a hot summer day it typically stays off for 15-20 minutes between cycles. I'm under the impression that the hard start kits can/will reduce that inrush of current substantially?

 

[dougfamous]

A properly installed 5-2-1 kit should be fine for the AC. It will not help the fact that, as pecmsg pointed out, the unit appears to be too big for your generator to handle. If you got the generator just for emergencies, then you really don't need to be running the AC during a power outage anyway. Was the generator installer aware of the size of the AC when they installed it? Was it originally supposed to be on the generator, or did you add it later? Might want to invest in a larger generator.

 

[pecmsg]

I generally will be running the refrigerator, a small deep freeze and maybe some lights. This is an emergency backup generator used for, well you know, an emergency. Obviously the outside temp determines how long the unit is off between the cycles and my thermostat is one of those fancy ones. It won't allow quick cycles. There is always some delay. In any case on a hot summer day it typically stays off for 15-20 minutes between cycles. I'm under the impression that the hard start kits can/will reduce that inrush of current substantially?

A refrigerator, freezer and A/C on a 40amp gen NO WAY

If you get it started the inrush voltage is dropping to the other appliances. Forget the A/C too big of a load or get a bigger generator.

Also please keep in mind anything with a computer doesn't like the dirty power cheep generators put out. A lot of newer small appliances have some type of computer in them.

 

[dmarkh]

A refrigerator, freezer and A/C on a 40amp gen NO WAY

If you get it started the inrush voltage is dropping to the other appliances. Forget the A/C too big of a load or get a bigger generator.

Also please keep in mind anything with a computer doesn't like the dirty power cheep generators put out. A lot of newer small appliances have some type of computer in them.

Thanks pecmsg, I'm still in the process of readying this gen set for the house. I can easily change out the 10kw gen head for a 15kw gen head but I haven't determined it's required yet. But your input has certainly opened my eyes. I was under the impression that the inrush current would be cut quit a bit with this hard start kit. Why do you say it is higher that what my meter reads?

Thanks

 

[Poodle Head Mikey]

The inrush current spike will not be substantially less with a start-component arrangement on your unit - what will change is that the duration of the current spike will be shorter.

PHM
------

Thanks pecmsg, I'm still in the process of readying this gen set for the house. I can easily change out the 10kw gen head for a 15kw gen head but I haven't determined it's required yet. But your input has certainly opened my eyes. I was under the impression that the inrush current would be cut quit a bit with this hard start kit. Why do you say it is higher that what my meter reads?

Thanks

 

[dmarkh]

A refrigerator, freezer and A/C on a 40amp gen NO WAY

If you get it started the inrush voltage is dropping to the other appliances. Forget the A/C too big of a load or get a bigger generator.


Also please keep in mind anything with a computer doesn't like the dirty power cheep generators put out. A lot of newer small appliances have some type of computer in them.

Would a generator that can handle a 70 amp surge suffice for this?

Thanks
Mark

 

[NCHeat]

Why do you say it is higher that what my meter reads?

Thanks

The inrush of amperage happens so fast that most meters cannot catch it. If you have an old analog meter you will be able to see the spike more clearly

 

[catmanacman]

anytime you are running ac's or heat pumps on generator its best to use a start kit and in your situation i would use the oe 260 start kit

 

[dmarkh]

The inrush of amperage happens so fast that most meters cannot catch it. If you have an old analog meter you will be able to see the spike more clearly

I have a modern amp clamp with a "MAX" button that supposedly shows the "MAX" draw. Can I not trust that?

Thanks
Mark

 

[dmarkh]

anytime you are running ac's or heat pumps on generator its best to use a start kit and in your situation i would use the oe 260 start kit

Since I already had the "5-2-1", I went ahead and installed it this morning. My meter, that had indicated 50-55 amps before the hard start kit, now after several cycles today it reads between 18 and 23 amps. Can't return the 5-2-1 but I can certainly still purchase the oe 260 kit.

Thanks
Mark

 

[beenthere]

Your amp meter is not fast enough to read the true starting amp draw. The compressor draws the same amount of amps with a hard start kit as it did without one.

 

[dmarkh]

Your amp meter is not fast enough to read the true starting amp draw. The compressor draws the same amount of amps with a hard start kit as it did without one.

I'm sure the compressor does draw the same amount but doesn't some of that amperage come from what is stored in the hard start cap? And then that amount not be coming from the line?

Mark

 

[rcstl]

Hard start and capacitor are phase shifters. The are delaying the power to the secondary winding. The hard start changes the relationship to the primary voltage. Others will be along but power use remains, just shifted.

 

[hurtinhvac]

I'm sure the compressor does draw the same amount but doesn't some of that amperage come from what is stored in the hard start cap? And then that amount not be coming from the line?

Mark

No. Just leave it as you have it and judiciously decide what you will run during the rare emergency. You don't need to run your deep freeze non stop, right? It will say frozen for a while and by then maybe the power is back. Maybe it will be during mild temps and you won't need conditioning at all for a brief time etc.

 

[beenthere]

I'm sure the compressor does draw the same amount but doesn't some of that amperage come from what is stored in the hard start cap? And then that amount not be coming from the line?

Mark

Nope. It doesn't store any of the power/amps.

 

[catmanacman]

emerson makes a soft start kit that would be your best solution although the hard start shoud be fine