Terminal “a” wiring details for economizers – Honeywell COMMERCIALPRO TB7220U User Manual

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TB7220U COMMERCIALPRO™ PROGRAMMABLE THERMOSTAT

3

62-0221—05

Fig. 5. Restrict wires to shaded area of wire hole.

Table 2. Terminal Designation Descriptions.

NOTES:

1.

When used in a single-transformer system,
leave metal jumper wire in place between RC
and R. If used on a two-transformer system,
remove metal jumper wire between RC and R.

2.

Common wire is optional when thermostat is
used with batteries. When using separate
transformers for heating and cooling, the
common must come from the cooling
transformer.

3.

If thermostat is configured for a heat pump in
the Installer Setup, configure changeover
valve for cool (O-factory setting) or heat (B).

4.

Reference economizer literature for wiring
details. When set for economizer operation,
the A terminal provides the occupancy signal.
(Power indicates occupied.)

5.

Sensor wires must have a cable separate
from the thermostat control cable.

Terminal “A” Wiring Details for
Economizers

— Wire the A terminal to the W7212 “N” terminal, or the

W7459 “TR” terminal.

— When using dual transformers at the thermostat, the

cooling transformer must power the economizer.

— The A signal is powered from the RC terminal and

energizes the economizer to signal occupied status
and drive the damper to the set minimum position.

Table 3. Wiring Diagrams.

WALLPLATE

M22266

WALL OPENING

WIRE

SHADED AREA

Terminal Designation

Description

RC (see Note 1)

Power for cooling—connect to secondary side of cooling system transformer.

R (see Note 1)

Power for heating—connect to secondary side of heating system transformer.

Y

Compressor output.

C (see Note 2)

Common wire from secondary side of cooling system transformer.

W

Heat relay.

G

Fan relay.

W2

Second stage heat relay.

Y2

Second stage cooling.

O/B (see Note 3)

Changeover valve for heat pumps.

A (see Note 4)

Economizer/Time-Of-Day (TOD) output—powered via RC terminal.

S1 (See Note 5)

Optional outdoor or indoor remote sensor.

S2 (See Note 5)

Optional outdoor or indoor remote sensor.

W1

Auxiliary Heat Relay Output (Head Pump Mode 2H/1C, 3H/2C)

System Type

Wallplate

Terminal

Identifications

Wiring

Diagram

Figure

Standard Heat/Cool

Conventional

6, 7

Heat Only

Conventional

8

Heat Only with Fan

Conventional

9

Cool only

Conventional

10

Standard Multistage
up to 2 Heat/2 Cool

Conventional

11, 12

Heat Pump
(No Auxiliary Heat)

Heat Pump

13, 14

Heat Pump
(with Auxiliary Heat)

Heat Pump

15, 16

Multiple TR21 Sensors

17, 18, 19

Multiple C7189U Sensors

20

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