"hard start" on AC

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I had my A.C./heat pump serviced today. The tech is suggesting adding something called a "hard start" to the compressor starting circut which supposedly reduces wear on the motor. And costs almost $200.
I have never heard of this. Have any of you and is it a good idea?
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Rich Greenberg Sarasota, FL, USA richgr atsign panix.com + 1 941 378 2097
Eastern time. N6LRT I speak for myself & my dogs only. VM'er since CP-67
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On 12/8/2011 1:44 PM, Rich Greenberg wrote:

http://lmgtfy.com/?q ¬+hard+start
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Thanks for this link, which led me to Google which led me to suppliers.
It seems that the hard start is a good idea, but they are charging a lot for them. Only $40-50 if I install it myself.
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Rich Greenberg Sarasota, FL, USA richgr atsign panix.com + 1 941 378 2097
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On 12/8/2011 2:44 PM, Rich Greenberg wrote:

It's an extra capacitor and start relay. $200.00 is 2 to 4 times what I would charge if I added it on during the same call. ^_^
TDD
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On 8 Dec 2011 15:44:13 -0500, snipped-for-privacy@panix.com (Rich Greenberg) wrote:

A hard start is usually used for compressors that are "hard to start" usually close to end of life. It is basically just a capacitor. I hope you get a reach around too for that $200. You can buy the kit retail for about $30 and the HVAC guy pays about $10. Hook up 2 wires.
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I've heard of hard start kits. I use them when the outdoor unit compressor won't start. If yours works, save your money. As a couple other techs have said, the guy is a bit over priced, too. I'd gently pass, on this one. And look for another tech.
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Thanks all for your responses. Unit has been working fine so I am going to (probably) pass on getting the hard start unit. My house lights do not dim when the unit starts which I understand is one of the symptoms of needing the hard start. But just to make sure, I will call the manufacturer (Rheem).
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Rich Greenberg Sarasota, FL, USA richgr atsign panix.com + 1 941 378 2097
Eastern time. N6LRT I speak for myself & my dogs only. VM'er since CP-67
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On Dec 9, 1:05 pm, snipped-for-privacy@panix.com (Rich Greenberg) wrote:

If it needed a hard start kit when operating normally, don't you think Rheem would have put one in?
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On 12/9/2011 12:05 PM, Rich Greenberg wrote:

If you have a digital thermostat, see if there is a start up delay that can be programmed into it for keeping the compressor from short cycling. I set them anywhere from 3 to 5 minutes. If the power blinks or the AC stops after reaching its set-point and someone immediately sets the temp down calling for cooling, the time delay prevents the compressor from trying to start before systems pressures equalize allowing the compressor to start under the least load. If you have a mechanical thermostat, a timer can be added out at the condensing unit inside the electrical junction box. In rural areas where power go out frequently during storms, I'll add anti short cycle timers and surge arresters to the inside and outside units to protect the capacitors and circuit boards.
TDD
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On Dec 8, 2:44 pm, snipped-for-privacy@panix.com (Rich Greenberg) wrote:

A hard start kit for the compressor is ONLY needed if the compressor doesnt come online right away when a call for cooling occurs by the thermostat . It is useful for tight old compressors or for low voltage conditions and/or for a/c systems that dont equalize the internal pressure quick enough before the next cooling cycle occurs. $200 installed is a tad on the high side unless hes going to be servicing the whole unit at the same time.
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Hello, I have a Rheem heat pump, model Rpnl-043jaz. The lights in my house all flicker every time it goes on....Will the hard start kit resolve this problem?
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On 6/8/2016 10:09 PM, snipped-for-privacy@gmail.com wrote:

Can't hurt. How much is the AC company charging?
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wrote in message
Hello, I have a Rheem heat pump, model Rpnl-043jaz. The lights in my house all flicker every time it goes on....Will the hard start kit resolve this problem?
****Your question is will the hard start kit help any, Well I will say with experience that I had it will not hurt any. However must likely your service is undersize, you could have line to long between your property and transformer that is someplace on the poll. Usually what you are describing the supply line is not large enough to give amount of current at startup, remember startup could be four (4) times running condition, so start up kit could help but eliminate “NO”
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On Wed, 8 Jun 2016 19:09:57 -0700 (PDT), snipped-for-privacy@gmail.com wrote:

A hard start might actually make that worse. It does just what it implies. It adds an extra capacitor to the motor to kick it harder on the start. This is used when the compressor is getting old and will not kick over reliably on it's own.
If your connections are solid from the utility, it may just indicate that your service conductors are too long or too small.
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snipped-for-privacy@aol.com says...

That was my thoughts also. That the hard start kit might make it worse as it should cause the motor to draw more current on startup. Unlike some devices that ramp up the motors slowly.
Could be loose connections of the house wiring or just too small of wire feeding the house.
I don't know about the Rheem unit, but I was looking at some of the Trane units and they have what seems to be a hard start kit already in them.
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On Thu, 9 Jun 2016 08:41:20 -0700 (PDT), Uncle Monster

It is worth being sure there is not this kind of protection in the unit or in the thermostat already. They seem pretty ubiquitous these days.
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On Thursday, June 9, 2016 at 12:56:43 PM UTC-4, snipped-for-privacy@aol.com wrote:

Or that maybe the cap that is there is going bad? Has that been checked?
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snipped-for-privacy@aol.com

A slight flickering is normal on central hvac startup, depending on the size of the unit and the panel amperage rating. If the unit is equipped with a hard start pack, it may not cause any flickering/dimming effect when powered up.
If it doesn't have this hard start pack though, it could cause the flicker/dimming without anything actually being 'wrong' with the OPs electrical system.
On a dead stop, the motor is pulling more amps than it would during a run phase; a considerable amount more, actually. The additional (but temporary) request for more amps is causing the temporary flickering or dimming effect. A hard start kit if properly installed and of sufficient size for the compressor it's going to be used with, should reduce if not outright eliminate the dimming effect because it's taking some of the load stress off the power source. Atleast, that's been my experience and that of others I know who do hvac professionally for a living. <--- I'm not hvac, I'm electrical/IT.
I'm confused about why you wrote that installing a hard start could make it worse? I would think the opposite would occur. It's reducing the load being placed on the panel by the compressor when it's used.
http://preview.tinyurl.com/gpb5dhk
http://www.achrnews.com/articles/119718-the-case-for-hard-start-kits
It's the same concept as placing a cap into your cars electrical system so that the amplifier you just had to have won't seriously dim your headlights and/or stallout the car when a bass note of sufficient strength hits at a decent volume.

It may also indicate nothing. As, like I said before, the initial power required for starting an electric motor from a dead stop is several amps more than it's going to pull once it's up and going. Considering that the compressor motor is actually pushing a fluid/gas around with resistance to the process, it's going to pull a considerable amount of amps to get rolling.
https://www.amazon.ca/SUPCO-SPP6-Start-Relay-Capacitor/dp/B0002YTLFE
The comment:
4 of 4 people found the following review helpful 5.0 out of 5 stars Easy install & Can hear the different with the A/C performance May 15 2014 By K K - Published on Amazon.com Verified Purchase My street has only 2 electrical transformers and 15 new houses have been put in the past 2-3 yrs so the power coming into the house does vary a bit depending on load on the central lines.
When the A/C used to kick on, the lights in the house dimmed and the A/C unit took 3-6 secs to be running at full speed. Since installing this, the lights don't dim when it kicks on and the A/C unit is running at speed in 2-3 secs. The sound of the A/C unit is now constant with no humming/buzzing anymore. Unit is just over one yr old on my one yr townhouse.
The reason I shared that comment about a hard start kit is because that has also been my experience when I've installed them on a few machines, to reduce 'flicker' effect. I've never seen one make the situation worse as they don't cause MORE of a power drain on startup, they eliminate some of it.
It's also entirely possible I've missed something here and I respect your electrical expertise, so I'm asking why in your professional opinion you think that installing a hard start kit could make the flickering/dimming situation worse and not improve it?
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MID: <nb7u27$crn$ snipped-for-privacy@boaterdave.dont-email.me>
Hmmm. I most certainly don't understand how I can access a copy of a
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On Sunday, August 28, 2016 at 1:54:39 AM UTC-4, Diesel wrote:

Agree with your other points, but not this one. When you put a cap in a DC circuit on the power input to an amplifier, it does act as a reservoir. It's fully charged during light or normal loads, when the amp has a sudden increase in power needed, that cap can supply some of it and being close to the destination, it can do so without the impedance effects of many feet of wire.
However, I don't think a hard start kit works that way. If it did, it could only be effective for 1/120 of a second, because that's all the initial charge that's there prior to starting will last. After that the AC voltage has reversed, the cap is drained, there is no reserervoir and it's being charged in the opposite direction. Current is needed through the AC supply to go into the cap and to supply the motor which is trying to start. So, unless the motor gets over it's starting difficulty in 1/120 of a second, I don't see how the cap can be helping by being a reservoir like it is in a DC circuit. I think the hard start kit probably works by creating more phase shift to the start winding, which will go on as long as the cap is in the circuit.

Agree. Best evidence of this is that they are often installed when the motor has started blowing fuses. That's what happened with my old AC. Once the kit was put in, no more blown fuses for 15 more years until it was replaced, while still working. If it increased the demand instead of moderating it, you'd have blown fuses, tripped breakers, and they wouldn't work.
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"trader_4" wrote in message

Agree with your other points, but not this one. When you put a cap in a DC circuit on the power input to an amplifier, it does act as a reservoir. It's fully charged during light or normal loads, when the amp has a sudden increase in power needed, that cap can supply some of it and being close to the destination, it can do so without the impedance effects of many feet of wire.
However, I don't think a hard start kit works that way. If it did, it could only be effective for 1/120 of a second, because that's all the initial charge that's there prior to starting will last. After that the AC voltage has reversed, the cap is drained, there is no reserervoir and it's being charged in the opposite direction. Current is needed through the AC supply to go into the cap and to supply the motor which is trying to start. So, unless the motor gets over it's starting difficulty in 1/120 of a second, I don't see how the cap can be helping by being a reservoir like it is in a DC circuit. I think the hard start kit probably works by creating more phase shift to the start winding, which will go on as long as the cap is in the circuit.
*** I am sorry but you need little more knowledge about Capacitors And how are used. In his application capacitor is always drained and it is use for two reasons to limit current and keep compressor running in "right direction" in AC systems. In DC system are used as surge or spiking Limiters and yes it could be use as instantaneous supply like in Cameras are even car start up but they always must be connected to source before it can be used that is why you need to wait to charge before your flash on camera will work and if capacitor start to leak you lose both. This Capacitors are call (ELECTROLYTIC) they are not consider Caps.

Agree. Best evidence of this is that they are often installed when the motor has started blowing fuses. That's what happened with my old AC. Once the kit was put in, no more blown fuses for 15 more years until it was replaced, while still working. If it increased the demand instead of moderating it, you'd have blown fuses, tripped breakers, and they wouldn't work.
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