Rapid 2005 Installation, operation & service manual - page 109
SECTION 17: E
LECTRICAL
99 of 147
17.
8
.3 MUA / Exhaust Failsafe Interlock
This option incorporates the lo
w
temperat
u
re limit
w
ith o
v
erride timer and an exha
u
st fan airflo
w
s
w
itch
monitor. The exha
u
st fan airflo
w
s
w
itch is field
pro
v
ided and field
w
ired as per the option sheet
s
u
pplied
w
ith the
u
nit. When the air handler is t
u
rned
on there is a 5 min
u
te establishing period for the lo
w
temperat
u
re limit s
w
itch and the exha
u
st fan
interlock. If the air handler’s discharge temperat
u
re
falls to the predetermined lo
w
temperat
u
re limit
setpoint, after the 5 min
u
te establishing period, the
air handler fan
w
ill be t
u
rned off. If there is a fail
u
re of
the exha
u
st fan to acti
v
ate the field s
u
pplied airflo
w
s
w
itch, after the 5 min
u
te establishing period, the air
handler fan
w
ill be t
u
rned off. To reset the
MUA/exha
u
st failsafe interlock, set the fan s
w
itch to
off and then on again. The air handler
w
ill ret
u
rn to
the normal seq
u
ence of operations.
3C
AFS-3
TD5
TIMING RELAY
TD5
21
3D
CR3
CR3
LOW PRESSURE
SWITCH 0.3 in. w.c.
20
CONTROL RELAY
AIR FLOW SWITCH
2
3B
LIMIT
TAS-3
LOW TEMP
TIMING RELAY
TD6
TD6
3A
SET AT 5 MIN
SET AT 5 MIN
AIR FLOW SWITCH
EXHAUST FAN
RED
YELLOW
-AFS-3: FIELD LOCATE ON EXHAUST FAN, SWITCH PROVIDIED BY OTHERS
-LOW TEMP LIMIT LOCATED AT DISCHARGE SIDE OF BLOWER
-TO TEST: SET DIAL TO MIN TEMP UNIT OPERATES
SET DIAL TO MAX TEMP UNIT SHUTS DOWN
NOTE:
-LOW PRES. SWITCH (BETWEEN WIRES 1 AND 20) REPLACES
LOW PRES. SWITCH (BETWEEN WIRES 8 AND 8A)
-CR3 RELAY NORMALLY OPEN CONTACTS REPLACE LOW PRESSURE SWITCH
ON MAIN WIRING DIAGRAM (BETWEEN WIRES 8 AND 8A)
25A
25
CLOGGED FILTER WIRING FOR SDC (80010) AND DTC (80000)
REMOTE PANELS
CR4
CR4
2
CR3
8
8A
REPLACES LOW PRESSURE
SWITCH ON MAIN WIRING
1
xxxx
xxxxxxxxxx
DIAGRAM
FIELD WIRED BY OTHERS
xxxxxxxxxxx
Part Number
Description
Models
01004
MUA/Exha
u
st Failsafe Inlock
All Models