T7200D,E, T7300D,E,F AND Q7300 SERIES 2000 PROGRAMMABLE COMMERCIAL THERMOSTATS AND SUBBASES
63-4355—1
8
Table 6. Terminal Designations (continued).
a
Some OEM models reverse the economizer terminal designations A1 and A2.
b
Some OEM models label the terminal for transformer common B.
1. Loosen the terminal screws on the subbase or wallplate
and connect the system wires. See Fig. 9.
IMPORTANT
Use 18-gauge, solid-conductor color-coded
thermostat cable for proper wiring. If using
18- gauge stranded wire, no more than ten wires
can be used. Do not use larger than 18-gauge wire.
2. Securely tighten each terminal screw.
3. Push excess wire back into the hole.
4. Plug the hole with nonflammable insulation to prevent
drafts from affecting the thermostat.
Standard
Terminal
Designations
Alternate
Terminal
Designations
Typical Connection
Function
Terminal
Type
W2
H2, R4, W3, Y
Stage 2 heating relay
Output
24V powered
contact
W3
—
Stage 3 heating relay
Output
24V powered
contact
X
B
b
, C, X1, X2
Common
Input
X1, X3
A, A1, A2, C,
L, X, Z
User defined Light Emiting Diodes (LEDs)
Annunciation
—
X4
—
LED common
Annunciation
—
Y1
C1, M, Y
Stage 1 compressor contactor (Q7300C, D)
Output
24V powered
contact
Y1, Y
RS, M
Stage 1 cooling compressor (Q7300A, G, L)
Output
24V powered
contact
Y2
C2
Stage 2 cooling compressor (conventional).
Stage 2 compressor contactor (heat pump).
Output
24V powered
contact
Y3
—
Stage 3 cooling compressor
Output
24V powered
contact
BM
—
ML7984 Actuator connection (Q7300L only); no call for
heat, valve closed; call for stage 1 heat, valve
approximately one-half open; call for stage 2 heat, valve
fully open.
Output
—
FC
—
Fan control transformer (Q7300L only)
Input
—
GH
—
High-speed fan output (Q7300L only); activate during calls
for cooling
Output
24V powered
contact
GL
—
Low-speed fan output (Q7300L only); acti-vated on calls for
heat and fan On selection.
Output
24V powered
contact
P1, P2
—
Pump interlock relay (Q7300L only); operates circulator
pump in hydronic heat or energizes conventional heat
system.
Input, Output
24V powered
contact
RM
—
ML7984A Actuator connection (Q7300L only); no call for
heat, valve closed; call for stage 1 heat, valve
approximately one-half open; call for stage 2 heat, valve
fully open.
Output
—
—
C, H, L
HSII Control Panel
—
—
—
O
Momentary circuit changeover
—
—
—
P
Defrost
—
—
—
R1, R2
Low- and high-speed fan relays
—
—
—
T
External temperature readout, T-relay; outdoor thermistor
—
—
