Table of Contents
Advertisement
1100
1200
5 kw
0.00
0.00
7.5 kw
0.00
0.00
10 kw
0.00
0.00
15 kw
0.00
0.02
20 kw
0.02
0.03
70
60
50
40
30
20
10
0
-20
de-energize, compressor will turn off for another 30 sec, and the
outdoor fan will stay off for 40 sec, before starting in the Heating
mode.
B. Defrost
The defrost control is a time/temperature control which includes a
field-selectable time period (DIP switch 1 and 2 on the board)
between defrost cycles of 30, 60, 90, or 120 minutes (factory set at
30 minutes).
To initiate a forced defrost, two options are available depending on
the status of the defrost thermostat.
If defrost thermostat is closed, speedup pins (J1) must be shorted
by placing a flat head screw driver in between for 5 sec and
releasing, to observe a complete defrost cycle. When the Quiet
Shift switch is selected, compressor will be turned off for two 30
sec intervals during this complete defrost cycle, as explained
previously. When Quiet Shift switch is in factory default OFF
position, a normal and complete defrost cycle will be observed.
If defrost thermostat is in open position, and speedup pins are
shorted (with a flat head screw driver) for 5 sec and released, a
short defrost cycle will be observed (actual length is dependent
ELECTRIC HEAT PRESSURE DROP TABLE
LARGE CABINET: 042-060
1300
1400
1500
1600
0.00
0.01
0.02
0.03
0.01
0.02
0.03
0.04
0.01
0.02
0.03
0.04
0.03
0.04
0.05
0.06
0.04
0.05
0.06
0.07
Balance Point Worksheet
Based on Entering Indoor Air of 70 Deg. F and Rated CFM
-10
0
10
Outdoor Air Temp (Deg F)
Fig. 26—604B Balance Point Worksheet
CFM
1700
1800
1900
2000
0.04
0.05
0.06
0.07
0.05
0.06
0.07
0.08
0.05
0.06
0.07
0.08
0.07
0.08
0.09
0.10
0.08
0.09
0.10
0.11
20
30
40
upon the selected Quiet Shift position). When Quiet Shift switch is
in ON position, the length of defrost is 1 minute (30 sec
compressor off period followed by 30 sec of defrost with com-
pressor operation). On return to heating operation, compressor will
again turn off for an additional 30 sec and the outdoor fan for 40
sec. When the Quiet Shift is in OFF position, only a brief 30 sec
cycle will be observed.
If it is desirable to observe a complete defrost in warmer weather,
the defrost thermostat must be closed as follows.
1. Turn off power to outdoor unit.
2. Disconnect outdoor fan motor lead from OF2 on control
board. (See Fig. 28) Tape to prevent grounding.
3. Restart unit in Heating mode, allowing frost to accumulate
on outdoor coil.
4. After a few minutes in Heating mode, liquid line tempera-
ture should drop below closing point of defrost thermostat
(approximately 30°F).
NOTE: Unit will remain in defrost until defrost thermostat
reopens at approximately 80°F coil temperature at liquid line or
remainder of defrost cycle time.
—22—
2100
2200
2300
0.08
0.09
0.10
0.09
0.10
0.11
0.09
0.10
0.11
0.11
0.12
0.13
0.12
0.13
0.14
50
60
2400
2500
0.11
0.12
0.12
0.13
0.12
0.13
0.14
0.15
0.15
0.16
060
048
042
036
030
024
C03008
Advertisement
Table of Contents
