Table of Contents
Advertisement
WIRING – MAIN POWER
Refer to the unit rating plate for wire sizing information
and maximum fuse or "HACR" type circuit breaker size.
Each outdoor unit is marked with a "Minimum Circuit
Ampacity". This means that the field wiring used must be
sized to carry that amount of current. Depending on the
installed KW of electric heat, there may be two field power
circuits required. If this is the case, the unit serial plate will
so indicate. All models are suitable only for connection
with copper wire. Each unit and/or wiring diagram will be
marked "Use Copper Conductors Only". These instructions
must be adhered to. Refer to the National Electrical Code
(NEC) for complete current carrying capacity data on the
various insulation grades of wiring material. All wiring
must conform to NEC and all local codes.
The electrical data lists fuse and wire sizes (75° C copper)
for all models including the most commonly used heater
sizes. Also shown are the number of field power circuits
required for the various models with heaters.
The unit rating plate lists a "Maximum Time Delay
Relay Fuse" or "HACR" type circuit breaker that is to
be used with the equipment. The correct size must be
used for proper circuit protection and also to assure that
there will be no nuisance tripping due to the momentary
high starting current of the compressor motor.
The disconnect access door on this unit may be locked
to prevent unauthorized access to the disconnect. To
convert for the locking capability, bend the tab located
in the bottom left-hand corner of the disconnect
opening under the disconnect access panel straight
out. This tab will now line up with the slot in the door.
When shut, a padlock may be placed through the hole
in the tab preventing entry.
See "Start Up" section for important information on
three phase scroll compressor start ups.
See Tables 3 & 4 for Electrical Specifications.
Low Voltage Connection
These units use a 24-volt AC low voltage circuit. The
"RT" terminal is the 24V transformer output, and the
"R" terminal is the 24VAC hot terminal for the operation
of the equipment. "RT" and "R" are connected with
brass jumper bar which can be removed and "RT" and
"R" connected to external NC (normally closed) contact
such as a fire/smoke detector that will cause immediate
shutdown of the equipment upon activation.
"C" terminal is grounded.
"G" terminal is the fan input.
"Y" terminal is the compressor input for cooling
1-Stage units only
"W1" terminal is the 1st stage electric heat.
"W2" terminal is the 2nd stage heat (if equipped).
"E", "F", "Y2" & "A" Used with ECONWMT Economizer.
"1" NO (normally open) lockout alarm.
"2" NC (normally closed) lockout alarm.
"3" COM lockout alarm.
"4" & "5" dirty filter alarm NC (normally closed).
Manual 2100-585A
Page
12 of 19
"6" Used with MD4000 only; do not use for anything else!
"Y1" & "7" Used with ECONWMT Economizer; do
not use for anything else!
"8" & "9" ECON Fail Alarm.
WIRING – LOW VOLTAGE WIRING
230/208V, 1 phase and 3 phase equipment dual primary
voltage transformers. All equipment leaves the factory
wired on 240V tap. For 208V operation, reconnect
from 240V to 208V tap. The acceptable operating
voltage range for the 240 and 208V taps are:
TAP
240
208
NOTE: The voltage should be measured at the field
power connection point in the unit and while
the unit is operating at full load (maximum
amperage operating condition).
For H model units with T or W vent option economizers,
refer to the MV4000 Series Lead/Lag Controller manual
2100-571 for low voltage connections diagrams.
Factory installed T and W vent option are wired per
Figure 7 of 2100-571. T and W vent option economizers
CAN NOT be used with MD4000 Lead/Lag Controllers.
For H model units with F or G vent option economizers,
refer to the MD 4000 Series Lead/Lag Controller
manual 2100-574 for low voltage connections diagrams.
F and G vent option economizers MUST be used with
the MD4000 Lead/Lag Controller. No other Lead/
Lag Controller or thermostat is compatible with this
economizer. Factory installed F and G vent option
economizers are wired per Figure 2 of 2100-574.
DIRTY FILTER SWITCH & RELAY
These units include a dirty filter switch and relay. The
alarm output of relay is normally closed, open on alarm
and is connected to terminals 4 and 5 of the unit low
voltage terminal block.
ECONOMIZER FAIL TIME DELAY RELAY
NOTE: Applies only to units with economizers.
These units employ a time delay relay used in
conjunction with the 100% Economizers to provide an
economizer fail alarm. The alarm output is connected
to terminals 8 and 9 of the low voltage terminal block.
The time delay should be set to no less than 3 minutes
to ensure no nuisance alarms.
TIMER TO BE
SET HERE
RANGE
253 – 216
220 – 187
MIS-3054
MIS-3054
Advertisement
Table of Contents
