Looking to power HVAC

[Supervstech]

It's a train, 220v so its 2 20amp breakers. One for each phase

Yup its two 5 ton units, I know this because we are good friends with our HVAC guy. He helps us out when we have questions or problems. We have had to replace the Capacitor on the Condents are unit twice. That was something we could do ourselves. But we contacted him for troubleshooting and everything. And he told us what part to get and where it was and how to replace it. So I know for sure that each one is a 5 ton. The house is a L shape. So each unit handles separate zones. It's a total of 6 breakers between the 2 units. A twenty breaker for each of the air handlers. And 2 breakers for each of the outside condensers And they're 20 amps on each side. Mind you. These units are R22 refrigerant. And we checked the pressures whenever it gets too hot in case it's leaking. And we found that they're not leaking the pressures. Or within the correct range. It's just so hot here that they can't keep up. We've had it up to a 109 And that's not the heat index.

I would love to see some pictures of the data panels on those Trane units.

Also, pressure is only part of the formula to know if the system is low on refrigerant. To know exactly how the unit is functioning, I need accurate line temperatures and line pressures.
Both suction and liquid side.
Also, ambient temp, indoor temp, and wet bulb temp indoors.
A good cfm reading on the unit, and air temps before and after the coil make a perfect diagnostic set.

 

[RCinFLA]

It is possible to have 20 amp compressor breakers for variable speed inverter units but that is lower than they should be (30 amps for 5 ton variable speed unit).

A normal PSC compressor would have 40-50 amp breakers to survive startup surge current.

For a 5 ton, 240vac unit, there will be a current of 13-17 amps for compressor run current. 20 amp breakers are too close to the edge.

Anyway, you are looking at 9-10 kW's, including air handler blower power, for two operating 5 tons units on a hot afternoon.

 

[gisean04]

I would love to see some pictures of the data panels on those Trane units.

Also, pressure is only part of the formula to know if the system is low on refrigerant. To know exactly how the unit is functioning, I need accurate line temperatures and line pressures.
Both suction and liquid side.
Also, ambient temp, indoor temp, and wet bulb temp indoors.
A good cfm reading on the unit, and air temps before and after the coil make a perfect diagnostic set.

you are correct, we did all that. my dad is the certified HVAC tech, not me. we still consult our friend because he stays current on everything.
there are a lot of replies from people I can't get them all but I have some updates. I asked the old man for more details. one unit is a 3.5 ton and the other is a 2.5 ton. @RCinFLA I was looking at signature solar's 9kw pallet of 300W panel for $2789. i have the space to put up 2 pallets all facing south. There are extra buildings almost attached to the house that have roofs facing south. but I don't know all the details on what will be needed for safe operation. i get that I can plug in the solar planes into an EG4 18kW and attach the loads. i can do the math for watts use and that size breaker is needed. but what let's will I need like a way to stop gird feedback during a power outage. or any of the other stuff that I don't know to ask about. I'm attaching a drone shot of the house its a bit old. We now have a large carport between the buildings and the house.

 

[RV10flyer]

It is possible to have 20 amp compressor breakers for variable speed inverter units but that is lower than they should be (30 amps for 5 ton variable speed unit).

A normal PSC compressor would have 40-50 amp breakers to survive startup surge current.

For a 5 ton, 240vac unit, there will be a current of 13-17 amps for compressor run current. 20 amp breakers are too close to the edge.

Anyway, you are looking at 9-10 kW's, including air handler blower power, for two operating 5 tons units on a hot afternoon.

My American Standard 5 ton Variable Speed 20 SEER units have an RLA of 27.5A. They get a 40 or 50 amp breaker.

 

[RV10flyer]

you are correct, we did all that. my dad is the certified HVAC tech, not me. we still consult our friend because he stays current on everything.
there are a lot of replies from people I can't get them all but I have some updates. I asked the old man for more details. one unit is a 3.5 ton and the other is a 2.5 ton. @RCinFLA I was looking at signature solar's 9kw pallet of 300W panel for $2789. i have the space to put up 2 pallets all facing south. There are extra buildings almost attached to the house that have roofs facing south. but I don't know all the details on what will be needed for safe operation. i get that I can plug in the solar planes into an EG4 18kW and attach the loads. i can do the math for watts use and that size breaker is needed. but what let's will I need like a way to stop gird feedback during a power outage. or any of the other stuff that I don't know to ask about. I'm attaching a drone shot of the house its a bit old. We now have a large carport between the buildings and the house.

Now you are down in the 6 ton/6,000W range for A/C.

 

[Supervstech]

you are correct, we did all that. my dad is the certified HVAC tech, not me. we still consult our friend because he stays current on everything.
there are a lot of replies from people I can't get them all but I have some updates. I asked the old man for more details. one unit is a 3.5 ton and the other is a 2.5 ton. @RCinFLA I was looking at signature solar's 9kw pallet of 300W panel for $2789. i have the space to put up 2 pallets all facing south. There are extra buildings almost attached to the house that have roofs facing south. but I don't know all the details on what will be needed for safe operation. i get that I can plug in the solar planes into an EG4 18kW and attach the loads. i can do the math for watts use and that size breaker is needed. but what let's will I need like a way to stop gird feedback during a power outage. or any of the other stuff that I don't know to ask about. I'm attaching a drone shot of the house its a bit old. We now have a large carport between the buildings and the house.

This size makes more sense, but still 20A breakers are small even for a 3.5 ton unit. I would still like to see pictures of the unit data labels.

 

[gisean04]

This size makes more sense, but still 20A breakers are small even for a 3.5 ton unit. I would still like to see pictures of the unit data labels.

I can look if it has one still, but I can plan for a larger breaker if it really needs it but it has been on the current one for years. and they aren't hot. we have 2 sets of breakers on it. one set outside at the unit so you can shut it down without going inside, and a set in the main breaker box. I was thinking today of using a smaller inverter like this one right? just for the A/C might upgrade to the 18K later. I can still use a 6k for another project on the property.

EG4 6K Off-Grid Split Phase Inverter | 6000EX-48HV | 6000W Output | 7500W PV Input | 500V VOC Input | Split Phase 120/240VAC​

 

[Vigo]

Here's an attic-centered video from a Texas homebuilder you might find interesting. Obviously it's a huge topic but this covers some of it.

 

[Just John]

It's a 14 SEER unit replaced in 2015 for $3200 installed. My average monthly bill is $185 (utility allows me to pay the average adjusted twice a year), and it can keep up with Phoenix heat. I'm very comfortable with my choices and my situation.

Yes, I also have a 3-ton unit with SEER 17 installed at about that time. It can keep up with the heat, but the humidity can be a problem during the monsoon season. I've installed a 12,000 BTU minisplit that I let run on low, which really helps with that. The old unit was 10 EER and 2.5-ton unit, it had problems on scorching days. It was about the same price due to the fact the utility gave me a $700 rebate at the time (combined gas heater and A/C in the attic).

FYI, 109 is NOT a really hot day in Phoenix.

 

[Supervstech]

I

I can look if it has one still, but I can plan for a larger breaker if it really needs it but it has been on the current one for years. and they aren't hot. we have 2 sets of breakers on it. one set outside at the unit so you can shut it down without going inside, and a set in the main breaker box. I was thinking today of using a smaller inverter like this one right? just for the A/C might upgrade to the 18K later. I can still use a 6k for another project on the property.

EG4 6K Off-Grid Split Phase Inverter | 6000EX-48HV | 6000W Output | 7500W PV Input | 500V VOC Input | Split Phase 120/240VAC​

Would need to see the dataplate on the unit to know if this inverter could power it.

I'm working on a 2013 2.5 ton unit right now... it is on a 25A breaker and it has a 16.8 minimum circuit requirement for wire sizing. That us just over 4000W, and the startup surge without a soft start will be in the 13,000W range...
So... unless you are installing a soft start on the equipment, I do not believe that inverter will start the systems...

 

[gisean04]

I
Would need to see the dataplate on the unit to know if this inverter could power it.

I'm working on a 2013 2.5 ton unit right now... it is on a 25A breaker and it has a 16.8 minimum circuit requirement for wire sizing. That us just over 4000W, and the startup surge without a soft start will be in the 13,000W range...
So... unless you are installing a soft start on the equipment, I do not believe that inverter will start the systems...

Thank you that's extremely helpful, How do you calculate the surge? I don't see it on the sticker. I understand that the draw would be (25 × 120) x 2 Giving me a 6000 watt usage.

 

[Supervstech]

Thank you that's extremely helpful, How do you calculate the surge? I don't see it on the sticker. I understand that the draw would be (25 × 120) x 2 Giving me a 6000 watt usage.

If you look at the label under the compressor specs, there are two numbers, RLA 12.8A and LRA OF 64.0A
LRA is what the compressor alone will draw, the fan also will be drawing at startup, so around another 8 or so amps…
Unless you have a soft starter, or you have an inverter driven compressor that slowly ramps up…

 

[RV10flyer]

If you look at the label under the compressor specs, there are two numbers, RLA 12.8A and LRA OF 64.0A
LRA is what the compressor alone will draw, the fan also will be drawing at startup, so around another 8 or so amps…
Unless you have a soft starter, or you have an inverter driven compressor that slowly ramps up…

My micro air soft start delays compressor startup 3 seconds after odf s/u, but my hyper engineering and Copeland brand labels do not have delay. A plus for the more expensive Micro Air, plus BT. The other two units are inverter (variable speed everything).

 

[Supervstech]

This is the new unit I'm installing, it has the new SEER2 rating of 14.3 SEER2
Notice the LRA is higher at 71.3, but the RLA is lower at 11.7
Lower min circuit as 15.2A with a lower max breaker of 20A.
So, if your 2015 3.5 ton isn't a 17SEER or higher, I imagine the 20A breaker is incorrect.

 

[RV10flyer]

This is the new unit I'm installing, it has the new SEER2 rating of 14.3 SEER2
Notice the LRA is higher at 71.3, but the RLA is lower at 11.7
Lower min circuit as 15.2A with a lower max breaker of 20A.
So, if your 2015 3.5 ton isn't a 17SEER or higher, I imagine the 20A breaker is incorrect.

That is the highest test pressure I’ve seen on any unit! Maybe that means the coils are built out of thicker or stronger tubing. The outdoor coils hold up pretty well for me on American standard. It’s the indoor coils that I’ve had problems with over the years. Also Mortex mobile home coils.

 

[gisean04]

Ok so I went ahead and ordered the 2 pack with load center of EG4 6500ex-48.

EG4 13kW Off-Grid Split Phase Inverter Bundle | 2 x 6500EX-48| 13000W Output | 16000W PV Input | Split Phase 120/240VAC | All in One Solar Inverter System [BNDL-E6500-2]

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL

signaturesolar.com

And 9kw of solar panels, I'll order another pallet when I can afford to. Got to buy all the stuff to wire the everything up. What we decided on doing was to first power our RV's With any remaining back feeding into the house. I now have to figure out how and what safety equipment I need to install is in order to pass inspection. The load center comes with a pv disconnect switch on each side and breakers. I'm struggling to find what is required for texas Is grid thai solar systems. I know that there has to be some anti feedback In the event of a grid outage to not back feed on to line workers. I just can't find any documentation on how to achieve that. I'm still waiting on signature solar people to get back to me with the same information. I check with my local utility and they want you to submit a plan on what you're proposing. They will get back to you if they have any concerns changes et cetera. And of course it all must get inspected and signed off on by an electrician. Right now, the only thing that's coming to mind is a auto transfer switch like generac use for critical loads. I had one before, It was analog And required grid power in order to move the internal connector back. Anyone have suggestions or links? Right now i'm reading the Is national electrical standards that the states Is adopt for their code.

 

[Scrugs]

Interesting about the attic insulation.... I need to get it quoted.

I was searching for information to help design a small solar array that is scalable with the intent to power a hybrid mini split that does not need an inverter or a battery and by doing so to start to learn about solar power. Prefer to install something that will be scalable to eventually power an EV and possibly the whole house.

I have a 3500 sq ft home recently purchased last year (it was actually a good deal). it has a fairly new AC unit (lennox ml14xp1 unit). I think i is a 5 ton, i am not 100% sure. The home is an older home and I need to improve the air flow between the rooms by installing some door vents to allow better air flow. I noticed the attic insulation is very old and I am sure not efficient.

Knowledge is power. Ignorance is expensive.

 

[Scrugs]

after a google search


The Lennox ML14XP1 is a single-stage heat pump designed to deliver affordable and efficient comfort. Here are the key features:

1. Efficiency: The ML14XP1 has an efficiency rating of up to 16 SEER (Seasonal Energy Efficiency Ratio) for cooling and up to 8.2 HSPF (Heating Seasonal Performance Factor) for heating. This makes it energy-efficient and cost-effective12.
2. Quantum™ Coil: The heat pump features the Quantum™ Coil, which is made from a proprietary aluminum alloy exclusive to Lennox. Rigorously tested under extreme conditions, this coil is designed to withstand harsh weather elements1.
3. Dual-Fuel Compatibility: When paired with a compatible Lennox furnace, the ML14XP1 creates a dual-fuel system that can automatically switch between electricity and gas based on cost-efficiency and weather conditions13.
4. Warranty: Merit models come with a 5-Year Limited Warranty on compressors and a 5-Year Limited Warranty on covered components. An extended 10-Year Warranty is available with product registration1.
5. Energy Star Qualified: The ML14XP1 is ENERGY STAR® Qualified, ensuring energy savings and environmental responsibility1.

 

[Scrugs]

the house has natural gas, but how to know if the heater is gas or electric ? the manual says it has both options

 

[glandpuck]

I didn't read the entire thread, but our Trane 5 ton (60,000 BTU) XV20i condenser unit (not the blower motor or the evaporative coils) has an LRA of 16 and an RLA of 19 amps at 240 volts 1 phase in USA. Rated at 20-22 SEER. On a 40 amp circuit.