MAX A/C with Single-Phase Power

[ME27272727]

Anyone aware of larger light-commercial DX split system / gas heat AHUs greater than 5-tons that don't require 3-phase power? It appears all the manufacturers typically jump from single to 3-phase after 5-tons. I'm working on an addition that has a large open space with 20-ton cooling load and high ventilation requirement, so hacking it up with multiple smaller residential type A/C units not a path I want to proceed with. The existing electrical service is a 240V/120V, typical residential type for USA. Seeing what my options are before investigating an upgrade in the electrical service.

Thank you.

 

[willard3]

As a general rule, motors larger than 5 hp are three-phase in the USA.

You may able to get larger than 5 hp single-phase, but it will be special order and expensive.

 

[LittleInch]

Single phase to 3 phase convertors don't look cheap....

https://www.larsonelectronics.com/p-149684-.aspx

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[itsmoked]

You may able to get larger than 5 hp single-phase, but it will be special order and expensive.

You left out: enormous

Keith Cress
kcress -

http://www.flaminsystems.com

 

[itsmoked]

Thinking about it, you're going to need to go non-linear for this. The only way to skin this cat is to use the night. Chill water for a longer, lower power requirement. This can also reduce the power bill if you have time-of-use by doing as much chilling at night as possible.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[lukaiENG]

Or you could bite the bullet and upgrade the incoming electrical feed and main power panel AKA not bodging it.

Does the incoming 120V power supply even have enough current carrying capacity to add this relatively large AC load as well as everything else in the building? I would suspect not.

 

[EnergyProfessional]

Did you check if the existing E-service is sufficient anyway? You add an addition with lighting and other uses. Single phase or not, the amperage may not suffice one way or another.
Assuming that service is old, is the equipment even serviceable and code-compliant? IME it is nearly impossible to get spare parts for old services.

We have few older buildings that had 240V single phase services. Once they needed new equipment it turned out the 1950's service were in such bad shape that they needed replacement anyway and we went with 3-phase.

 

[Drazen]

You couldn't accomplish what you stated with multiple smaller units anyhow.

the idea of single-phase units is to be fitted to typical residential power schemes, typically being the largest electrical consumer in a residence.

With multiple such units, there is no any chance your electrical installation can handle it, and if you going to rework it, than single-phase has no reasoning any more.

 

[DrRTU]

Two (2) sets of twinned furnaces (bottom or both side rtn) or 2 Reznor/Sterling/Modine roof mounted indirect furnaces with Two 5 ton ACCUs off to the side. Stage the ACCUs. Captive air does this with multiple 5 ton ACCUs ontop of the AHU. 5 ton single phase are very poor at starting. This all assumes they have a large single phase main power service. We have done this in old office buildings with multiple 200a services.