Outdoor Wiring
Wiring the Outdoor Unit
Line Voltage Wiring
The Inverter products require line voltage with a ground from a service disconnect. Voltage connects at the line voltage terminal block in the lower right corner of the control box. This terminal block can accommodate 8 gauge wire, preferably stranded wire in a commercially available whip. Voltage should be standard single phase 208/230V.
The National Electric Code specifies that wire size between the breaker and the unit be sized to handle the Minimum Circuit Ampacity of the equipment. Too many electricians, technicians, and even local inspectors try to size the wire for the breaker. Wire size is not as simple as 15 amps for 14 Gauge, 20 Amps for 12 gauge, and 30 amps for 10 gauge and so on. Type of wire, length, ambient temperature wiring is exposed to, and how many wires in the conduit, all play into sizing wire. If you do not own a copy of the NEC, it would be a good idea to purchase one.
Regarding a similar subject, breaker size should be sized from the minimum breaker size to the maximum breaker size, or anywhere in between. There is no code that says you may only use the maximum breaker size. Local codes may be more stringent than the NEC, but they can’t be more liberal. That is to say, they can’t demand the breaker be sized for the maximum, when the NEC states a smaller breaker can be used. Minimum and Maximum breaker sizes are printed on the unit rating plate.
Communicating Low Voltage
It is highly recommended to wire the system communicating using EcoNet. Low voltage wiring is made simply by connecting R, C, E1, and E2 to the green wire terminals on the bottom left of the control board. The green terminal blocks are removable to make connections easier. Be sure to remain consistent in wire colors between equipment. It’s best not to have a bunch of wire nuts beyond that required to hook up the air handler.
Communication circuits use E1 and E2. Common is closely tied to these so installing a second transformer in the outdoor unit because there aren’t 4 wires in the bundle is prohibited. You will need to run 4 wires from the indoor unit to the outdoor unit. The last thing you want is sketchy operation which almost always results in parts changing until someone points out the problem as being improperly wired.
Legacy Low Voltage Wiring
If for some reason you have elected to wire the system with legacy connections, and accept that diagnostics, staging and overall performance will be negatively impacted, you will connect all connections on the low voltage terminals. For Heat pumps this means R, C, Y, Y2, B and W. For straight cooling you will still need R, C, Y, and Y2. Legacy wiring should be limited to emergency use.
Utility connections
UTIL and UTIL24 are provided as a convenience when a system is wired with EcoNet and a utility load shedding device is installed by the power company. The utility simply provides a dry set of contacts. Should this be used, the technician or utility service provider will need to configure the utility connections in the EcoNet thermostat. Please see the EcoNet thermostat instructions on how to access this. There is a downloadable letter that describes these instructions for the utility company since they are generally the only ones authorized to make these connections.
Links
Below are links to the wiring diagram found in the equipment, along with a link to the desired utility letter.
