Bryant ERVBBLHU1150, Installation, Start-Up, And Operating Instructions Manual, Page: 9 / 16

V. LOW-SPEED AIR EXCHANGE
When low-speed air exchange occurs, K1 relay closes and K2
(12–vdc relay) is de-energized. This keeps low-speed relay con-
tacts closed and high-speed contacts open. Then, 115vac is applied
between red and gray wires on Molex plug (pins 1 and 4) and the
motor runs in low-speed operation. Also, 115vac is applied across
ins 5 and 7, energizing interlock relay (See Fig. 16).
CARE AND MAINTENANCE
WARNING: ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing or servicing system, always turn off
main power to system. There may be more than 1
disconnect switch.
CAUTION: CUT HAZARD
Failure to follow this caution may result in personal
injury.
Sheet metal parts may have sharp edges or burrs. Use care
and wear appropriate protective clothing and gloves when
handling parts.
Fig. 12–Balancing ERVBBLHU
A05043
TEMPORARY
FLO W COLLAR
STALE AIR
TO OUTSIDE
FRESH AIR SUPPLY
TO BUILDING
BALANCING
DAMPER
FRESH AIR
FROM OUTSIDE
STALE AIR RETURN
FROM BUILDING
Fig. 13–Magnehelic Gage
A98400
MAX
MIN
AIRFLOW
DIRECTION
CONVERSION
CHART
MAX
MIN
ZEROING SCREW
FLOW
COLLAR
TABLE 3–DEFROST CYCLE
OUTSIDE TEMPERA-
TURE °F
STANDARD DE-
FROST (AS SHIPPED)
EXTENDED DE-
FROST (JUMPER
JU1-F REMOVED)
Above 23°F No Defrost No Defrost
23°F to 5°F
6 Minute Defrost/60
Minute Exchange
10 Minute Defrost/30
Minute Exchange
4°F to -17°F
6 Minute Defrost/32
Minute Exchange
10 Minute Defrost/20
Minute Exchange
Below -18°F
6 Minute Defrost/20
Minute Exchange
10 Minute Defrost/15
Minute Exchange
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