Disconnect for A/C condensor unit

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Old 09-01-16, 12:41 PM
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Disconnect for A/C condensor unit

Hi guys,

I'm installing a Pioneer split type air conditioner (WYE018GMFI15RL):
Power source: 208-230V~ 60Hz, 1Ph
Minimum circuit ampacity: 14A
Max. Fuse: 20A

I've installed the 220 circuit on a 20A double breaker and this leads to the exterior GE 30 Amps disconnect (model TF30R). The disconnect needs 2 fuses in the handle. Fuses allowed are H, K1, K5, K9, RK1, RK5.

The Big Question: What AMP size fuses should I use? 2x 20A or 2x 10A


The Small Question: Will any of the mentioned classes suffice (H, K1, K5, K9, RK1, RK5)?

I appreciate your help!
 
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Old 09-01-16, 01:27 PM
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You could just leave the 30A fuses in there.
 
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Old 09-01-16, 01:36 PM
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There are no fuses in the handle right now so there's nothing to leave there.

Also, 30A fuses would exceed the 20A max fuse limit, wouldn't it?
 
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Old 09-01-16, 01:54 PM
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Since minimum circuit Ampacity is 14 amperes you cannot use a 10 ampere fuse. I would use the smallest slow-blow fuse, starting with 15 ampere, that will allow the unit to start reliably, not going over 20 ampere.
 
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Old 09-01-16, 02:09 PM
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Okay! I was asking because two (hot) 110v lines go into the disconnect and I didn't know if you add up the two fuses that are used. Following your advice I will start with two 15 amp fuses. Thanks!
 
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Old 09-01-16, 02:49 PM
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Just for the record you have 240v not 220v. There are no 110 lines running to the disconnect. There are the two 240 volt legs of the power supplied to your house running to the disconnect.
 
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Old 09-01-16, 03:39 PM
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I would use 15A fuses.

You should have installed a 30A or 60A non-fused disconnect as the circuit is protected by the 20A circuit breaker.
 
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Old 09-01-16, 07:13 PM
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Thanks for the 'record' Ray2047. So if I would measure one leg it would read 240v?
 
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Old 09-01-16, 07:26 PM
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I'll use 15A fuses. But why should I have used a non-fused disconnect as you suggest?
 
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Old 09-01-16, 08:03 PM
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The two pole 20A breaker is all your unit requires for protection. You are double protecting your unit. It won't hurt anything it's just not required or necessary.

The only place you'd have to use a fused disconnect is if you had an existing 30A circuit and you needed to protect your A/C at a lower current.
 
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