Step-up 208v single phase to 230v single phase for 1/8 HP fan motor 2

[Digger425]

Our grade school has 40 year old, Nesbitt thru-the-wall, low pressure, steam supplied air handlers. Each air handler serves one classroom and has one 1/8 HP, dual wound, 208/230v, single phase, double ended shaft motor which drives four squirrel cage blower wheels (two blowers on each shaft end).

Our supply voltage is 208 volts and the only double ended shaft motors we can find to replace the burned out motors are rated 230 volts, single phase. The 230v motors lack sufficient torque to bring the blowers up to speed in a timely manner resulting in high starting current for a prolonged period of time. Additionally once up to speed they draw greater than the motor's rated full load current.

Where can I purchase a 208/230v auto transformer or double wound transformer to boost the 208v supply to 230v? The transformer must be compact for it has to fit into the Nesbitt air handler located in the classroom.

If anyone has any other suggestions to overcome the problem I am facing, I would appreciate your sharing them with me. Winter is on its way and I need to supply heat for the students.

 

[davidbeach]

I don't know about size, and there are other locations that things can be mounted, but you can try Square D, Eaton, General Electric or Siemens and look for a buck/boost transformer. You should be able to get close to the desired voltage although you may not hit it exactly. A 230V motor will work fine at 240V, so if you have a choice of a bit below 230V and a bit above 230V, go for the combination that gets you the higher voltage.

 

[waross]

A 240V:24V buck boost rated should work.
The current capacity of the 24 volt winding should be adequate for the motor full load current. Expect 228.8 volts.
respectfully

 

[sreid]

You can purchase buck-boost transformers from McMasters.

http://www.mcmaster.com