Bryant DURAPAC PLUS SERIES 542J - Manual (Page 18)

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XI. STEP 11 — 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 contact to the 50 to 90 minute contact. At
the end of the time period, the defrost cycle will begin. See
Fig. 29.
START-UP
Use the following information and complete Start-Up Check-
list on page CL-1 to check out unit PRIOR to start-up.
I. UNIT PREPARATION
Check that unit has been installed in accordance with these
installation instructions and all applicable codes.
II. COMPRESSOR MOUNTING
Loosen compressor holddown bolts until sideways movement
of the washer under each holddown bolt head can be
obtained. Do not loosen completely, as bolts are self-locking
and will maintain adjustment.
III. INTERNAL WIRING
Check all electrical connections in unit control boxes; tighten
as required.
IV. REFRIGERANT SERVICE PORTS AND VALVES
Each 542J 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 dis-
charge line. Be sure all valves are open.
V. CRANKCASE HEATERS
Heaters are energized as long as there is power to unit.
IMPORTANT: Unit power must be on for 24 hours prior to
start-up. Otherwise, damage to compressor may result.
VI. INDOOR FAN
Fan belt and pulleys are factory installed. Remove tape from
the fan pulley and adjust pulleys on 542J150 units as
required. See Service section on page 23 for instructions on
adjusting indoor fan performance. See Table 9 for air quan-
tity limits. See Tables 10 and 11 for fan performance data.
Be sure that fans rotate in the proper direction. See Table 12
for static pressure drops for accessories and options. See
Fig. 30 and 31 for fan performance using horizontal adapter
and power exhaust. See Table 14 for fan rpm pulley settings.
See Table 16 for indoor-fan motor performance. To alter fan
performance, see Indoor-Fan, 542J150 Units and Indoor-Fan,
542J180 Units sections, pages 23 and 24.
Table 9 — Air Quantity Limits
*Minimum cfm is 5600 when electric heater is used.
UNIT 542J
MINIMUM AIRFLOW
(Cfm)
MAXIMUM AIRFLOW
(Cfm)
150 3750 6250
180 4500* 7500
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
Fig. 29 — Defrost Board Timer Wiring