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I−UNIT COMPONENTS
TCA unit components are shown in figure 1. All units come
standard with removeable unit panels. All L1, L2, and L3 wir-
ing is color coded; L1 is red, L2 is yellow, and L3 is blue.
A−Control Box Components
TCA control box components are shown in figure 2. The
control box is located in the compressor compartment.
1−Disconnect Switch S48 (field installed)
All units may be equipped with an optional disconnect switch
S48, or circuit breaker, CB10. S48 and CB10 can be a
toggle switch or a twist style switch. Both types can be used
by the service technician to disconnect power to the unit.
CB10 when use, will be in the same location as S48 on the
wiring diagram.
2−Terminal Strip TB2
All units are shipped with factory installed TB2. Units with-
out S48 or CB10 will have supply power connected to TB2.
3−Control Transformer T1 (all units)
All use a single line voltage to 24VAC transformer
mounted in the control box. Transformer supplies power
to control circuits in the unit. The transformer is rated at
70VA and is protected by a 3.5 amp circuit breaker
(CB8) which is located on the transformer itself. The
208/230 (Y) voltage
transformers have two
primary voltage taps,
but only one may be
used depending on
supply voltage. See
figure 3. 460 (G) and
575 (J) voltage trans-
formers use a single
primary voltage tap.
4−Contactor Transformer T18
T18 is a single line voltage to 24VAC transformer used in
4 compressor units only. Transformer T18 is protected
by a 3.5 amp circuit breaker (CB18) located on the transformer
itself. T18 is identical to transformer T1. The transformer
supplies 24VAC power to the contactors.
5−Terminal Strip TB1
All indoor thermostat connections will be to TB1 located on
MCC board A45. For thermostats with occupied and un-
occupied" modes, a factory installed jumper across termi-
nals A1 and A2 should be removed. Unit wiring is designed
for a three−stage thermostat. For two−stage applications
jumper between Y2 and Y3 on TB1.
6−Terminal Strip TB14
Terminal strip TB14 located on the MCC board A45 distrib-
utes 24V power from transformer T1 to the control box
components. Units not equipped with smoke detectors A17
or A64, will have a factory installed jumper across terminals
24VAC and R.
7−Outdoor Fan Capacitors C1, C2, C18 & C19
Fan capacitors C1, C2, C18, C19 are 10 MFD / 370V capac-
itors used to assist in the start up of condenser fans B4, B5,
B21, B22 respectively.
8−Outdoor Fan Relay K10 & K68
Outdoor fan relays K10 and K68 used in all units, are DPDT
relays with a 24VAC coil. In all TCA units K10 energizes con-
denser fans B4 and B5 and K68 energizes condenser fans
B21 and B22.
9−Fuses F10 and F6
Two line voltage fuses F10 provide overcurrent protection
to all condenser fans in all Y voltage TCA units and rated at
30A. Fuses F6 provide overcurrent protection for optional
field installed power exhaust fans and rated at 15A.
10−Compressor Contactor K1, K2 & K14 (all
units)
K146 (TCA 210H, 240H, 300S units only)
All compressor contactors are three-pole-double-break
contactors with 24VAC coils. In all TCA180, 210S and
240S units, K1, K2 and K14 energize compressors B1, B2
and B13 in response to thermostat demand. In the
TCA210H, 240H and 300S units, K1, K2, K14 and K146
energize compressors B1, B2, B13 and B20 in response
to thermostat demand.
11−Blower Contactor K3
Blower contactor K3, used in all units, is a three-pole-double-
break contactor with a 24VAC coil used to energize the indoor
blower motor B3 in response to blower demand. K3 is ener-
gized by relay KD on the A45 MCC board.
FIGURE 3
BLUE
YELLOW
ORANGE
RED
BLACK
230 VOLTS
208 VOLTS
PRIMARY
SECONDARY
208/230V TRANSFORMER
