Trane 4TCA4024A1000A Installer's Manual page 16

S S t t e e p p 4 4 — — U U n n i i t t I I n n s s t t a a l l l l a a t t i i o o n n
Table 6. Field Wiring Diagram
Notes:
1. Fused disconnect size,
power wiring and grounding
of equipment must comply
with codes.
2. Be sure power supply agrees
with equipment and heater
nameplate.
3. Low voltage wiring to be 18
AWG minimum conductor.
4. See heater nameplate for
current rating of heater
used.
5. See unit and heater
diagram for electrical
connection details.
6. Jumper must be connected
between 1 and 2 for fan to
operate in heating.
7. Some thermostats provide
the 'G' signal in the cooling
mode only. To provide the 'G'
signal in the heating mode
an accessory relay is
required. See fig. 3 for
proper connections.
8. For cooling only omit the
electric heater, associated
power wires and the 'W'
signal thermostat wire.
9. Fig. 4 demonstrates
connection of the two stage
electric heat thermostat
accessory only. For further
unit connection details refer
to the other figures.
10. The 41A (BR) wire is first
stage electric heat. If the
electric heater accessory has
two heating stages the 41C
(BR) wire is second stage
electric heat.
C C o o n n t t r r o o l l W W i i r r i i n n g g ( ( C C l l a a s s s s I I I I ) )
Low voltage control wiring should not be run in conduit
with power wiring unless Class 1 wire of proper voltage
rating is used. Route the thermostat cable or equivalent
single leads of No. 18 AWG colored wire from the
thermostat subbase terminals through the rubber
grommet on the unit. See Figures 1–6 for the control
entry (24V Entry) location. Make connections as shown
on Table 6, p. 16
Do not short thermostat wires since this will damage
the control transformer.
Refer to the table below for recommended wire sizes
and lengths for installing the unit thermostat. The total
resistance of these low voltage wires must not exceed
one (1) ohm. Any resistance in excess of 1 ohm may
16
from drw. D758087P01
cause the control to malfunction because of the
excessive voltage drop.
Table 7. Thermostat Wire Size and Maximum Length
Wire Size
18
16
14
I I m m p p o o r r t t a a n n t t : : Upon completion of wiring, check all
electrical connections, including factory
wiring within the unit, and make sure all
connections are tight. Replace and secure
all electrical box covers and access panels
before leaving the unit or turning on the
power to the unit.
Maximum Length (Ft)
75
125
200
88-4TCA4001-1C-EN