Terminal Function - Robertshaw 9520 User Manual

TERM EQUIPMENT TO CONNECT
C 24VAC common connection
L System fault indicator connection
R 24VAC hot connection
Y2 Second stage cooling connection
Y1 First stage compressor connection Yes
E Emergency heat connection
G Indoor fan connection
W2 Second stage heat connection
O Cool active reversing
valve connection
B Heat active reversing
valve connection
* For systems using a backup heat source. If separate E terminal connection is not available,
jumper E and W2.
** Most heat pump systems will have a cool active OR a heat active reversing valve. Use the
appropriate terminal.
TERMINAL LEGEND - 9520
REQ?
Yes For input of 24VAC common
side of transformer
No For connection of system
fault indicator (if present)
Yes For input of 24VAC hot side
of transformer
No Energizes on a call for
second stage cooling
Energizes on a call for first
stage heating or cooling
No* Energizes on a call for heat
in the EM mode only
Yes Energizes with E, Y1, Y2 and
W2 terminals or with FAN
option switched to the ON
position
No* Energizes on a call for
second stage of heat
(auxiliary heat)
Yes** Energizes when in the in
COOL mode
Yes** Energizes when in the
HEAT or EM modes
6

TERMINAL FUNCTION