Split System Fan Unit Disconnect

[JGirard]

Does the interior part of a mini Split system require a local disconnect? If so what would you use? I looked online at manufactures websites and even Youtube and no one seems to install a disconnect. Some youtube videos show running a cord from the outside to the inside unit and referring to it as the low voltage wire this sounds terrible. These interior units have three wires connected to them S1, s2, s3 and ground so if a disconnect is needed would we need to interrupt all three conductors. The unit I'm wondering is a residential 220 VAC 15 amp. Of course there would be a pull out at the outside unit.

 

[iwire]

I just did two and used a two pole switch.

It is what the directions show and it makes sense as in my case the third and forth wires were control wires that power for was created for in the indoor use. So if you open the two power wires there is no power on the control.

Of course check the directions and see what your model takes.

 

[Dennis Alwon]

In our area the disco is required and we use a dp switch also. I am not quite clear why it is needed other than some of the older units were wired for 30 amps and had heat strips. Some of the newer units have DC motor and are wired with thermostat wire.

 

[iwire]

I am not quite clear why it is needed other than some of the older units were wired for 30 amps and had heat strips.

There is a fan motor, in most cases things with motors need disconnects.

 

[Dennis Alwon]

There is a fan motor, in most cases things with motors need disconnects.

I agree for most motors a disco is needed but if it is 1/8 hp or less the overcurrent protective device for the branch circuit can be used. 430.1109(B)

I think those DC motors may fit the bill.

 

[augie47]

Locally, disconnects are most often required per 430.102
Also, in reference to your OP, cord is considerd by local inspectors to be a violatioon of 400.8

 

[beanland]

Wired per Manufacturer

Wired per Manufacturer

I just installed one and the manufacturer instructions show a disco between the 240V supply and the outdoor unit but just 3-#14+g from outdoor unit to indoor unit with no disco at indoor unit. Adding a disco between outdoor and indoor unit would violate manufacturer listing.

 

[kwired]

430.109(B) allows the branch circuit overcurrent device to be the disconnect if the motor is 1/8 HP or less.

430.102 covers location of disconnecting means for motor as well as motor controller. It does not cover location of branch circuit overcurrent device for motors of less than 1/8 HP.

 

[tom baker]

Washington does not require if for a single family dwelling and on the same floor.