Installation guide

NOTE:If thephasingis incorrecLthecontactorwill not be
energizeE To correct the phasing, interchange any 2 of the 3
power connections on the field side.
When themlostat is satisfied, its contacts open, de-energizing the
contactor and blower relay. Compressor and motors should stop.
NOTE: If indoor unit is equipped with a timeodelay relay circuiL
the blower runs an additional 90 sec to increase system efficiency.
Heating
On a call for heating, thermostat makes circuits RoY and R-G. If
phasing is correcL circuit R-¥ energizes coatactor, starting
outdoor-fan motor and compressor. Circuit RoG energizes indoor-
blower relay, starting blower motor on high speed.
---> Should temperature continue to fall, R-W2 is made through
second-stage room thermostat. (ircuit RoW2 energizes relays,
bringing on supplemental electric heat. If outdoor thermostat is
used (field-installed option), only the first bank will be energized.
Remaining bank of supplemental electric heat will be energized
when outdoor temperature f_lls below outdoor thermostat setting.
When thermostat is satisfied, its contacts open, de-energizing
coatactor and relays. All heaters and motors should stop.
Defrost
The def?ost control is a time/temperature control which includes a
fieldoselectable (quick-connects located at board edge) time period
between def?ost cycles (30, 50, or 90 minutes), factory set at 90
minutes.
Defrost mode is identical to cooling mode except that outdooro£m
motor stops and secondostage heat is turned on to continue
warming conditioned space.
---> Initially the defi'ost cycle timer starts when the contactor is
energized and a 24v signal is present on the T1 terminal. Then the
defrost cycle begins when the cycle timer times out (30, 50, 90
rain) and the defi'ost thermostat is closed.
To initiate defrost, the defi'ost thermostat must be closed. This can
be accomplished as %llows:
1. Turn off power to outdoor unit.
CONTACTOR
OFF,NO 24VAC
ON:OK
FLASH _PHASE PROBLEM
0 0 o
L3 L1
A00010
TaNe 2--Phase-Monitor LED Indicators
LED STATUS
No call for compressor
OFF
operation
FLASHING Reversed phase
ON Normal
Fig. 8--Phase-Nonitor Control
H9C1
_> O1
c_ usx-,( 1A
K1 J_ "U
E_
O0
OF2
<
_;2 DFT_? J2_ O
30 50 90
TI CC OF ]pl _1
h_ _ D _ DI 1
C
A02001
TaNe 3--Defrost Control Speedup-Timing
Sequence
NBNhqlUM MAXmMUM SPEEDUP
PARAMETER
{MINUTES} {_',_NUTES) (NONRNAL)
30-minute cycle 27 33 7 sec
50-minute cycle 45 55 12 sec
90-minute cycle 81 99 21 sec
10-minute cycle 9 11 2 sec
5 minutes 4.5 5.5 1 sec
Fig. g--Defrost Control
2. Disconnect outdoor-_im motor lead fi'om OF2 on control
board. (See Fig..) Tape lead 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 temperature
should drop below closing point of defl'ost thermostat (ap-
proximately 30°F).
5. Short between speed-up tem_inals with a flat-bladed screw-
&iver. (See Fig. 9.) This reduces the timing sequence to
1/256th of original time. (See Table 3.)
6. When you hear reversing valve change position, remove
screwdriver immediately; othepxise, contlot will tem_inate
nom_al 10-minute defrost cycle in approximately 2 sec.