24
Step 11 — Set Defrost Cycle — The defrost timer is
factory set at 30 minutes. The timer may be field-adjusted to
50 or 90 minutes by moving the wire from the 30-minute con-
tact to the 50 or 90 minute contact. At the end of the time
period, the defrost cycle will begin. See Fig. 39.
START-UP
Use the following information and complete Start-Up
Checklist on page CL-1 to check out unit PRIOR to start-up.
Unit Preparation — Check that unit has been installed in
accordance with these installation instructions and all applica-
ble codes.
COMPRESSOR MOUNTING — Loosen compressor hold-
down bolts until sideways movement of the washer under each
holddown bolt head can be obtained. Do not loosen complete-
ly, as bolts are self-locking and will maintain adjustment.
INTERNAL WIRING — Check all electrical connections in
unit control boxes; tighten as required.
REFRIGERANT SERVICE PORTS AND VALVES —
Each 50HJQ unit has 2 Schrader-type service ports per circuit;
one on the suction line and one on the liquid line. Be sure that
caps on the ports are tight. The units also have 2 service valves
per circuit; one on the suction line and one on the discharge
line. Be sure all valves are open.
CRANKCASE HEATERS — Heaters are energized as long
as there is power to unit.
INDOOR FAN — Fan belt and pulleys are factory installed.
Remove tape from the fan pulley and adjust pulleys on
50HJQ014 units as required. See Indoor-Fan, 50HJQ014 Units
section on page 31. See Table 10 for air quantity limits. See
Tables 11A, 11B, and 12 for fan performance data. Be sure that
fans rotate in the proper direction. See Table 13 for static pres-
sure drops for accessories and options. See Fig. 40 for fan per-
formance using horizontal adapter. See Table 14 for fan rpm
pulley settings. See Table 15 for indoor-fan motor performance
data. To alter fan performance, see Indoor-Fan, 50HJQ014
Units and Indoor-Fan, 50HJQ016 Units sections, page 32.
Table 10 — Air Quantity Limits
*Minimum cfm is 5600 when electric heater is used.
GLYCOL HYDRONIC COILS — Glycol coil is intended for
add-on type applications or new work where a boiler system is
available. Glycol coil and electric heat cannot be installed
together. Refer to Tables 16 and 17 for glycol coil data and
ratings.
OUTDOOR FANS AND MOTORS — Fans and motors are
factory set. Refer to Outdoor-Fan Adjustment section on
page 33 as required.
RETURN-AIR FILTERS — Check that correct filters are
installed in filter tracks. See Table 1. Do not operate unit with-
out return-air filters.
OUTDOOR-AIR INLET SCREENS — Outdoor-air inlet
screens must be in place before operating unit.
IMPORTANT: Unit power must be on for 24 hours prior to
start-up. Otherwise, damage to compressor may result.
UNIT 50HJQ MINIMUM CFM MAXIMUM CFM
014 3750 6250
016 4500* 7500
Fig. 39 — Defrost Board Timer Wiring
O
R
Y
T1
C
C
T2
CTD
LOGIC
90
50
30
DFT
TEST
OF1
DEFROST BOARD
DR
OF2
O
W2
R
Y
C
DEFROST
CYCLE TIME
ADJUSTMENT
WIRE
NOTE: The CRRFCURB013A00 horizontal supply and return
adapter accessory improves 50HJQ fan performance by increasing
external static pressure by amount shown above.
Fig. 40 — Horizontal Supply/Return Fan
Performance with CRRFCURB013A00
High-Static Regain Adapter
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