York 19 SEER Installation Manual Download Page 11

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5390862-UIM-A-0318

Johnson Controls Unitary Products

FIELD CONNECTIONS POWER WIRING

1. Install the proper size weatherproof disconnect switch outdoors and

within sight of the unit, per local code.

2. Remove the screws at the top and sides of the corner cover. Slide

the control box cover down and remove from unit.

3. Run power wiring from the disconnect switch to the unit.
4. Route wires from disconnect through power wiring exit provided

and into the unit control box as shown in Figure 1 and view the
openings in Figure 11.

5. Make the power supply connections to the contactor.

FIELD CONNECTIONS CONTROL WIRING

This system is equipped to be either serial communication capable
(COMM) or conventionally wired. First determine which setup you are
going to apply for the application, then follow the necessary steps.

DO NOT CUT THE LOW VOTAGE MOLEX PLUGS OFF UNTIL YOU
HAVE DETERMINED WHICH METHOD TO CONNECT TO.

• Conventional wiring consists of five wires leaving the control

board connected to (R, C, Y1, Y2, Y2OUT) where four wires end
up in a 12 pin Molex connector and the fifth wire is tied back on
the harness with heat shrink on the end.

• Serial Communication consists of four wires leaving the control

connected to (B-, C, R, A+) where four wires end up in a 4 pin
Molex connector.

You will only connect to one of the two harnesses. Leave the connector
on the harness not being used to prevent a possible short from the
24VAC to ground as some wires in both conventional and serial com-
munication have power applied from the other harness source depend-
ing on which is connected. Cut the Molex connector off of wiring
harness being used and connect the field low voltage wiring, using wire
connectors.
Terminals on the board from the following pin locations will have power
applied:
Communicating block (B-, C, R, A+); the R terminal/wire will have
24VAC.
Conventional block (R, C, Y1, Y2, Y2OUT); the R & Y2OUT terminal/
wires will have 24VAC.
If any of these connections have an unterminated wire at the end, it
needs to be properly capped to prevent a possible short to ground.

Conventional Wiring

1. Route the 24-volt control wiring (NEC Class 2) from the outdoor unit,

to the indoor unit, and to the thermostat in the steps below.

2. If utilizing the Demand Response or the Y2Lock feature, a minimum

of five thermostat wires will need to be ran to the outdoor unit from
the indoor equipment. If the features are not applied, only four wires
are needed.

3. Trace the harness out where it ends in a large 12 pin Molex con-

nector, inside the low voltage box. Clip the 12 pin Molex connector
and discard.

4. If utilizing the Demand Response or the Y2Lock feature, Y2out

needs to be connected to the indoor control to cycle between high
and low speed airflow. Pull the wire from under the label, strip the
end of it, and connect it to the thermostat wire. If you are not apply-
ing the features above, do not strip the end. Figures 16-21 indicate
proper wiring implementation.

5. Strip the remaining four wires that run to R, C, Y1, Y2 and make the

necessary thermostat connections, noted in the thermostat wiring
diagrams. Refer to Figures 16-21.

6. Replace the control box cover, removed in Step 2 of the FIELD

CONNECTIONS POWER WIRING procedures.

7. All field wiring should be in accordance with national electrical

codes (NEC) and/or local-city codes.

8. Mount the thermostat approximately 5 ft. above the floor, where it

will be exposed to normal room air circulation. Do not place it on an
outside wall or where it is exposed to the radiant effects from
exposed glass, appliances, drafts from outside doors, or supply air
vents.

Serial Communication Wiring

1. Route the 24-volt control wiring (NEC Class 2) from the outdoor unit,

to the indoor unit, and to the thermostat in the steps below.

2. Trace the communicating harness from the (B-, R, C, A+) block

where it ends in a 4 pin Molex connector, inside the low voltage
box. Clip the 4 pin Molex connector and discard.

3. Strip the four wires and make the necessary thermostat connec-

tions noted in the thermostat wiring diagrams. Refer to Figures 14 &
15.

FIGURE 12:

Typical 2-Stage Conventional Field Wiring - AC

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