AC TONS TO CURRENT

[mivey]

Much appreciated, thank you. But it still leaves the question of why they need the rating in tons. The POCO need to size the supply in Volts and Amps.

SOP or something. They probably have look-up tables or computer entries based on tons of A/C and that is the only way they have been shown to enter the data. These are probably by-the-book positions that have no authority or maybe the skills to change the routine.

 

[florida-sparkey]

COP is used for heaters while EER is used for cooling unit computations. The minimum EER IIRC is 11 for 2015. (EER = COP x 3.41).
In the OPs case with EER =11, KW = (48,000)/11 = 4363.63 kW or Amps = (4363.63/(240) =18.2 amps! Very near!

So I stumbled upon the correct answer after all LOL. Thanks for the explanation!

 

[florida-sparkey]

this may help
http://www.power-calculation.com/EER_SEER_COP_conversion_air_conditioning.php

Thanks! that has good explanations of the acronyms.

 

[kwired]

Besoeker, I see what you're getting at and why not just avoid asking for tons in the first place. Here's a typical Utility load form sheet that we have to fill out and provide the local POCO. See Sheet (2) for the typical equipment they're interested in for typical commercial development. http://www.oncor.com/EN/Documents/A...mer Requirements - Commercial Industrial.pdf

The Utility is interested in Tons / SEER rating info, but ours also is interested in the kW output.

I would think they are most interested in VA, that is what they need to be able to supply.

Much appreciated, thank you. But it still leaves the question of why they need the rating in tons. The POCO need to size the supply in Volts and Amps.

Probably goes back to the fact these things are marketed/sold according to how many tons of cooling they are rated to produce and not according to kw or kva. In fact they never have kw or kva stated on them, you need to calculate those values for yourself based on other information marked on them.

 

[Sahib]

In fact they never have kw or kva stated on them, you need to calculate those values for yourself based on other information marked on them.

It is because a hermetic compressor motor used in residence does not have shaft extension, unlike conventional motor, to measure HP.

 

[kwired]

It is because a hermetic compressor motor used in residence does not have shaft extension, unlike conventional motor, to measure HP.

Hp wasn't mentioned, but is another possible unit of measurement, as is joules/hour, calories/hour, foot-pound/hour, newton-meter/hour

 

[Besoeker]

It is because a hermetic compressor motor used in residence does not have shaft extension, unlike conventional motor, to measure HP.

As far as I am aware, and I have visited several electric motor manufacturing plants, measuring shaft power is routinely done on standard motors.

 

[MAC702]

OP is likely more interested in unit's rated input kVA then kW.

Probably just the former. Once he has that, he doesn't then need the latter.

 

[florida-sparkey]

Probably just the former. Once he has that, he doesn't then need the latter.

That is correct. Just need KVA. PF not relevant.

 

[MAC702]

That is correct. Just need KVA. PF not relevant.

I think he meant that. I was mostly teasing his misspelling. :ashamed:

 

[florida-sparkey]

I would think they are most interested in VA, that is what they need to be able to supply.

Probably goes back to the fact these things are marketed/sold according to how many tons of cooling they are rated to produce and not according to kw or kva. In fact they never have kw or kva stated on them, you need to calculate those values for yourself based on other information marked on them.

I fully agree with both of your comments kwired. As noted by someone else, they probably have a cheat sheet Tons to electric load worst case. They just want to figure the xformer load and voltage drop of the service wires. They always ask for all the values but I have gotten away with just giving tons in the past. This time I was trying to move the paperwork along with all data and also became curious about how it all equated.

 

[florida-sparkey]

I think he meant that. I was mostly teasing his misspelling. :ashamed:

Ha, I had to read 3 times to see it. Without spellcheck, I could not write my name.

 

[kwired]

I think he meant that. I was mostly teasing his misspelling. :ashamed:

I think I spelled it correctly but chose the wrong word