430648-JIM-D-1010
Johnson Controls Unitary Products
21
YC3
Piping And Electrical Connections
Piping connections are made from the rear of 7.5 thru 12.5 Ton
units and the front of 15 thru 20 Ton units. Connections can be
made directly to the suction and liquid line service valves.
With the piping connections being made at the rear of 7.5 thru
12.5 Ton units and front of 15 thru 20 Ton units, the piping can
be routed to the units from the left or right side.
Electrical connections for power and control wiring are made
from the front of the units, right or left of the 7.5 thru 12.5 Ton
electrical control box access or left of the electrical control box
access on 15 thru 20 Ton units. See Table 10 and Figures 8
and 11 for piping sizes and electrical knockout details.
Start-Up
Crankcase Heater
The crankcase heater must be energized at least 8 hours
before starting the compressor. To energize the crankcase
heater, the main disconnect switch must be closed. During this
8 hour period, the system switch on the room thermostat must
be “OFF” to prevent the compressor from starting. Make sure
that the bottom of the compressor is warm to the touch to prove
crankcase heater operation.
Pre-Start Check
Before starting the unit, complete the following check list:
1.
Have sufficient clearances been provided?
2.
Has all foreign matter been removed from the interior of the
unit (tools, construction or shipping materials, etc.)?
3.
Have the condenser fans been rotated manually to check
for free rotation?
4.
Are all wiring connections tight?
5.
Does the available power supply agree with the nameplate
data on the unit?
6.
Is the control circuit transformer set for the proper voltage?
7.
Have the fuses, disconnect switch and power wire been
sized properly?
8.
Are all compressor hold-down nuts properly secured?
9.
Are any refrigerant lines touching each other or any sheet
metal surface? Rubbing due to vibration could cause a
refrigerant leak.
10. Are there any visible signs of a refrigerant leak, such as oil
residue?
11. Has the refrigeration system been leak checked,
evacuated and had the correctly calculated charge
weighted in?
12. Is any electrical wire laying against a hot refrigerant line?
Initial Start-Up
1.
Supply power to the unit through the disconnect switch at
least 8 hours prior to starting the compressor.
Table 8:
J15YC/YD, J20YC/YD & J25YC Unit Height Dimensions
MODEL
A
J15YC
44.5
J15YD
44.5
J20YC
50.0
J20YD
50.0
J25YC
50.0
Table 9:
Piping And Electrical Connection Sizes (Inches)
MODEL
J07YC
J10YC
J10YD
J12YC
J12YD
No. Refrigeration Circuits
1
1
2
1
2
Suction Line OD (in.)
1 1/8
1 3/8
1 1/8
1 3/8
1 1/8
Liquid Line OD (in.)
5/8
7/8
5/8
7/8
5/8
Power Wiring Knockout
1 3/8
1 3/8
1 3/8
1 3/8
1 3/8
Control Wiring Knockout
7/8
7/8
7/8
7/8
7/8
MODEL
J15YC
J15YD
J20YC
J20YD
J25YC
No. Refrigeration Circuits
1
2
1
2
1
Suction Line OD (in.)
1 5/8
1 3/8
1 5/8
1 3/8
1 5/8
Liquid Line OD (in.)
7/8
5/8
7/8
5/8
7/8
Power Wiring Knockout
1 3/8
1 3/8
1 3/8
1 3/8
1 3/8
Control Wiring Knockout
7/8
7/8
7/8
7/8
7/8
Do not attempt to start the compressor without at least 8
hours of crankcase heat or compressor damage can
occur.
