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Electrical Data
General
1. Be sure the available power is the same voltage and phase
as that shown on the unit serial plate. Line and low voltage
wiring must be done in accordance with local codes or the
National Electrical Code, whichever is applicable.
2. Apply correct line voltage to the unit. A
7
⁄
8
" (22mm) or 1
1
⁄
8
"
(29mm) hole is supplied on the side of the unit. A discon-
nect switch near the unit is required by code. Power to the
unit must be sized correctly and have time delay (dual
element) fuses or an HACR circuit breaker for branch
circuit overcurrent protection. See the nameplate for
correct ratings.
230 Volt operation and 50 cycle units
All 208-230 volt single and three-phase units are factory
wired for 208 volt operation. For 230 volt operation, the line
voltage tap on the 24 volt transformer must be changed.
Disconnect and cap the red lead wire and interchange it with
the orange lead wire on the primary of the 24 volt trans-
former. Three-phase 50 cycle units require a neutral wire for
230/50/1 power.
Fan speed change
All units have two-speed fan motors and are shipped for
high speed operation. On unit sizes 007, 009 and 012, the
change from high speed to low speed is done by removing
the black wire from the fan relay and connecting the red wire
to the fan relay (Figure 4A). On units sizes 015 through 060,
each fan motor is supplied with a 5-pin terminal block
mounted on the fan motor. To change from high speed to
low speed, move the wire from the black #3 location to the
red #4 location on unit sizes 015 through 042 or to the red
#5 location on units sizes 048 and 060. On 575 volt units,
add a jumper between black #3 and blue #4 for low speed
operation. See Figure 4B.
Figure 4A.
Figure 4B.
1. All units are recommended to be connected to supply
and return piping in a two-pipe reverse return configura-
tion. A reverse return system is inherently self-balancing
and requires only trim balancing where multiple quanti-
ties of units with different flow and pressure drop char-
acteristics are connected to the same loop. A simple
way to check for proper water balance is to take a
differential temperature reading across the water con-
nections. To insure proper water flow, the differential
should be 10
o
F (5
o
C) to 14
o
F (8
o
C).
A direct return system may also be made to work ac-
ceptably, but proper water flow balancing is more diffi-
cult to achieve and maintain.
2. The piping can be steel, copper or PVC.
3. Supply and return runouts are usually connected to the
unit by short lengths of high pressure flexible hose which
are sound attenuators for both unit operating noise and
hydraulic pumping noise. One end of the hose should
have a swivel fitting to facilitate removal for service. Hard
piping can also be brought directly to the unit although
it is not recommended since no vibration or noise at-
tenuation can be accomplished. The hard piping must
have unions to facilitate unit removal. See Figure 5 for
typical piping setup.
4. Supply and return shutoff valves are required at each
conditioner. The return valve is used for balancing and
should have a “memory stop” so that it can always be
closed off but can only be reopened to the proper
Piping
position for the flow required.
5. No unit should be connected to the supply and return
piping until the water system has been cleaned and
flushed completely. After the cleaning and flushing has
taken place, the initial connection should have all valves
wide open in preparation for water system flushing.
6. Condensate piping can be steel, copper or PVC. Each
unit is supplied with a
7
⁄
8
" (22mm) ODM copper stub.
7. The condensate disposal piping must have a trap and
the piping must be pitched away from the unit not less
than
1
⁄
4
" inch per foot (21mm per meter). Generally, the
condensate trap is made of copper and soldered on the
unit. See Figure 6. A piece of vinyl hose from the trap to
the drain line is used for simple removal. A complete
copper or PVC condensate system can also be used.
Union fittings in the copper lines should be applied to
facilitate removal. Factory supplied condensate hose
assemblies have a
7
⁄
8
" (22mm) sweat to FPT fitting to
facilitate connection of a flexible vinyl, rubber or steel
braided hose.
8. No point in the drain system may be above the drain
connection of any unit.
9. Automatic flow controlled devices must not be installed
prior to system cleaning and flushing.
10. A high point of the piping system must be vented.
11. Check local code for the need for dielectric fittings.
RED (LOW SPEED)
BLACK (HIGH SPEED)
BROWN (CAPACITOR)
COMMON (WHITE)
FAN
MOTOR
FAN
MOTOR
YELLOW 1
BROWN 2
BLACK 3
*RED 4
*RED 5
COMMON
CAPACITOR
HIGH SPEED
LOW SPEED
LOW SPEED
JUMPER
*On unit sizes 048 and 060, terminal 4 is color-
coded blue and terminal 5 is color-coded red.