My proposed system can't power my AC

[SoundDaTrumpet]

Tesla says you will need a scroll type compressor to work with soft starter. They did shy away saying 140 LRA could not be backed up. The smaller 82 LRA they said could, but I did not have a scroll compressor. The AC units are on the other side of the house on their own subpanel so that would have been difficult. Add a 3rd Powerwall and it will be a sure thing.

 

[Frankman60]

My compressor is a scroll type according to the specification sheet and it is connected to a 50 amp breaker. Can someone point me to a good source for information on a soft starter? Is it something that requires an HVAC contractor to install?

 

[MP3Mike]

My compressor is a scroll type according to the specification sheet and it is connected to a 50 amp breaker. Can someone point me to a good source for information on a soft starter? Is it something that requires an HVAC contractor to install?

Any electrician should be able to install one.

I think this is the one most people have used: Hyper Engineering | Single Phase

 

[Frankman60]

I looked at the website and the installation instructions with photos. It doesn’t look too difficult to install following the step by step instructions. What is a good source for purchasing the product?

Any electrician should be able to install one.

I think this is the one most people have used: Hyper Engineering | Single Phase

 

[NuShrike]

I looked at the website and the installation instructions with photos. It doesn’t look too difficult to install following the step by step instructions. What is a good source for purchasing the product?

Check the distributors page. They vary by State.

 

[Frankman60]

Thanks. Is there a source for someone that is not an HVAC contractor? The links on the distribution page seem to be companies that require a contractor account.

Check the distributors page. They vary by State.

 

[cr0ntab]

Thanks. Is there a source for someone that is not an HVAC contractor? The links on the distribution page seem to be companies that require a contractor account.

I bought mine from here:

Sure Start SS1B16-32SN (16-32 RLA) – Ziller Electric

I use it on a 5 ton AC

2006 Trane XR 13
LRA 148
RLA 25

With 2 powerwalls and the soft start the system won't fire up.

However, if my solar is producing the little bit of extra power is enough to get the whole system to fire up and the powerwalls can do their thing. I tested this while flipping my main breaker off.

 

[nwdiver]

I would like a split system for the bedroom that would work in the case of
a protracted outage (hurricane) to sleep with at night.

I bought a 2 ton multi split for my house. IT. IS. AWESOME!

I can run off-grid with a 4.4kW Magnum inverter on 8 Golf Cart batteries. Does great. Split systems are inverter driven so there is no starting current. It's kinda funny because when I'm running off-grid my lights dip more when my refrigerator cycles than when my AC does.

CRAZY efficient too. the 9k BTU unit I have in my bedroom only uses ~500w when it's running at low speed.

 

[Frankman60]

Thanks. My compressors RLA is 27.5 so I would need the same Sure Start you have. I’m wondering how much the load is on the PWs other than the AC when it won’t start? The 2 PWs are capable of 10 kWs sustained power and that should be enough to handle the AC start IF the Sure Start reduces the start up load by the claimed 70 percent.

I bought mine from here:

Sure Start SS1B16-32SN (16-32 RLA) – Ziller Electric

I use it on a 5 ton AC

2006 Trane XR 13
LRA 148
RLA 25

With 2 powerwalls and the soft start the system won't fire up.

However, if my solar is producing the little bit of extra power is enough to get the whole system to fire up and the powerwalls can do their thing. I tested this while flipping my main breaker off.

 

[cr0ntab]

Thanks. My compressors RLA is 27.5 so I would need the same Sure Start you have. I’m wondering how much the load is on the PWs other than the AC when it won’t start? The 2 PWs are capable of 10 kWs sustained power and that should be enough to handle the AC start IF the Sure Start reduces the start up load by the claimed 70 percent.

It would be my regular house loads, so probably ~1kW

It doesn't help that my unit is 13 years old, I'm sure the starting current has gone up since it was new.

Once it kicks the bucket I'm definitely moving to an inverter/variable speed unit.

 

[hodad66]

 

[Dan123]

Thanks, got it. The LRA is 135. Does that mean that the compressor can draw up to 135 amps at start up? That seems too high. The specs for the compressor state: Minimum Circuit Ampacity = 35.9, Maximum Overcurent Device Amps = 60, and Minimum Overcurrent Device Amps = 40. I am going to assume that the compressor start up will overload two PWs but will a Sure Start soft starter allow the compressor to work with 2 PWs assuming no more than 2 kWs of concurrent other house load?

It should work, if you can get thus SureStart, but I don't know how SureStart works and which ACs are compatible.

 

[hodad66]

I just got off the phone with my AC people. They said that with an LRA of
58 that my unit probably already has a sure start. They also said that my
compressor is a scroll compressor.

 

[davecolene0606]

Down the street from you in Fort Pierce, 2 powerwalls 15K of PV Lenox AC. Easily starts, easily carries for a full night @ 74 degrees with normal usage of other appliances except the dryer. This is with PW set for a 10% reserve. PW’s full by 11:00am next sunny day.

I have gone “off grid” for a week and able to do it including charging our cars for around town driving. This takes a bit of hands on management by using the cars and house loads once the PW’s are “full”.

Very doable, I expect that when my neighbors generators go quiet after running out of gas/propane (took 48hours in 2004), they’ll be over for a light snack and a cold drink, they are welcome!

Let me know if you have more questions.

Fire Away!

 

[Frankman60]

My PW contractor told me today that 2 PWs will not overload when my AC compressor with an LRA of 135 connected to a 50 amp breaker starts when there is a grid outage. The PWs are presently being installed and they are going to test this by shutting off the main breaker and starting the AC after the installation is completed. The other backed up loads will be about 2 kWs during the test.

 

[hodad66]

My PW contractor told me today that 2 PWs will not overload when my AC compressor with an LRA of 135 connected to a 50 amp breaker starts when there is a grid outage. The PWs are presently being installed and they are going to test this by shutting off the main breaker and starting the AC after the installation is completed. The other backed up loads will be about 2 kWs during the test.

I'm hoping that I get better information when someone actually LOOKS at my
home and equipment!!

 

[Frankman60]

Today we tested how my AC system with a 135 LRA worked with the 2 PWs that were recently installed. In short, it did not work. This was the test. The main breaker was turned off to simulate a grid outage. PWs kicked in an supplied the power for the house load without a hiccup. The house load was about 2.5 kW and solar was only producing about 300 watts (early morning). We then turned on the AC. The compressor did not start but I could hear the relay click inside it. Lights dimmed in the house and my PV inverters shut down. Every 8 seconds the compressor tried to start (relay clicking) and the lights flickered. This kept repeating until I flipped the main breaker back on and when the grid was restored the AC compressor turned on and the solar inverters can back online. During the time that the AC compressor was trying to start, the PWs were still providing power to the house, but lights were flickering and motors slowed down on kitchen appliances. I was surprised that the PWs did not go off line completely.

I think I am going to try the Sure Start soft starter.

 

[SoundDaTrumpet]

Today we tested how my AC system with a 135 LRA worked with the 2 PWs that were recently installed. In short, it did not work. This was the test. The main breaker was turned off to simulate a grid outage. PWs kicked in an supplied the power for the house load without a hiccup. The house load was about 2.5 kW and solar was only producing about 300 watts (early morning). We then turned on the AC. The compressor did not start but I could hear the relay click inside it. Lights dimmed in the house and my PV inverters shut down. Every 8 seconds the compressor tried to start (relay clicking) and the lights flickered. This kept repeating until I flipped the main breaker back on and when the grid was restored the AC compressor turned on and the solar inverters can back online. During the time that the AC compressor was trying to start, the PWs were still providing power to the house, but lights were flickering and motors slowed down on kitchen appliances. I was surprised that the PWs did not go off line completely.

I think I am going to try the Sure Start soft starter.

I was very interested reading the above until you noted no Sure Start soft starter installed! What you describe matched exactly what the energy advisor said, AC unit just won't start. Early on, in my design, until it was determined my compressors are incompatible, Sure Starts were included in my design. Instead, my AC units are tied into the non-backup part, but they are monitored as a home load with CTs, so PW can power them when rates are high. I hope your compressor is compatible with Sure Start. Is Tesla planning to rewire the AC as a non-backup load?

 

[Frankman60]

I believe my compressor is compatible with Sure Start because it is a scroll type motor but I am going to check with the company to be sure. The contractor talked about possibly putting the AC in the non backed up load panel but I would prefer to have it backed up in case there is an extended grid outage during hot weather. I know I would have to use it judiciously but at least I could use it.

But you said something I need to know. Is my subpanel that is not backed up to the PWs being monitored and included in the data in the tesla app? I have a 50 and 60 amp circuit in the non backed up subpanel connected to EV chargers. No one mentioned to me that these loads would not be monitored and included with the backed up loads in the Tesla app.

I was very interested reading the above until you noted no Sure Start soft starter installed! What you describe matched exactly what the energy advisor said, AC unit just won't start. Early on, in my design, until it was determined my compressors are incompatible, Sure Starts were included in my design. Instead, my AC units are tied into the non-backup part, but they are monitored as a home load with CTs, so PW can power them when rates are high. I hope your compressor is compatible with Sure Start. Is Tesla planning to rewire the AC as a non-backup load?

 

[miimura]

I believe my compressor is compatible with Sure Start because it is a scroll type motor but I am going to check with the company to be sure. The contractor talked about possibly putting the AC in the non backed up load panel but I would prefer to have it backed up in case there is an extended grid outage during hot weather. I know I would have to use it judiciously but at least I could use it.

But you said something I need to know. Is my subpanel that is not backed up to the PWs being monitored and included in the data in the tesla app? I have a 50 and 60 amp circuit in the non backed up subpanel connected to EV chargers. No one mentioned to me that these loads would not be monitored and included with the backed up loads in the Tesla app.

You have to look and see where the Grid CTs are installed. When my system was originally installed, the Grid CTs were factory installed on the grid input to the Backup Gateway's transfer switch. Therefore, all my loads that remained in my main panel were not measured and the Powerwall system was oblivious to that usage. My independent installer came out and extended the wires for the Grid CTs and moved them to the main grid feed line between my meter and my main panel.

You will have to look and see where your CTs are installed in order to know what they are measuring.