Lennox G20RE Series, Руководство по обслуживанию, Страница: 4 / 14

Page 4
C – Blower Motors and Capacitors
All G20RE units use direct drive blower motors. All mo-
tors used are 120V permanent split capacitor motors to
ensure maximum efficiency. See table1 for ratings.
TABLE 1
G20R BLOWER RATINGS 120V 1PH
BLOWER MOTOR HP
Q2/3, Q3
Q4, Q3/4
Q5, Q4/5
CAP
3/4
1/2
1/3 5MFD 370V
7.5MFD 370V
40MFD 370V
D – Door Interlock Switch (S51)
A door interlock switch rated 16A at 125VAC is located
behind the BCC2-2 blower control panel. The switch is
wired in series with line voltage. When the blower door
access panel is removed the unit will shut down.
E – Blocked Vent Switch (S62)
The blocked vent switch (S62) is located on the right
side of the draft diverter. The switch is a high temper-
ature N.C. SPST manual-reset limit connected in se-
ries with the ignition control A3. It trips when there is
excess heat in the draft diverter or improper venting.
The switch is factory set at 300
°
+ 12
°
(149
°
C) and
cannot be adjusted.
F – Flame Rollout Switch (S47)
Flame rollout switch is a high temperature limit located
on top of the burner box. The limit is a N.C. SPST manu-
al-reset limit connected in series with the ignition con-
trol A3. When S47 senses rollout, the ignition control
immediately stops ignition and closes the gas valve. If
unit is running and flame rollout is detected, the gas
valve will close and ignition control will be disabled.
The switch is factory set and cannot be adjusted. See
table 2. The switch can be manually reset.
TABLE 2
FLAME ROLLOUT SWITCH SETPOINTS
HEATING INPUT KBTUH SETPOINT
50, 75
100, 125, 150
260
°
F + 12
°
F
300
°
F + 12
°
F
G – Primary Limit Control (S10)
The primary limit switch (S10) on all units is located in
the middle of the heating vestibule wall.
G20RQ2/3(X)E-50, Q3(X)E-75, Q4(X)E-75, Q3/4(X)E-100
and Q3(X)E-125 units use a SPST self resetting limit.
See figure 4. When excess heat is sensed in the heat ex-
changer, the limit switch will open and interrupt the
current to the gas valve. If the limit is tripped, BCC2-2
energizes the blower. The limit automatically resets
when unit temperature drops below the reset point.
See table 3.
INSULATING COVER (s)
FIGURE 4
G20RQ2/3(X)E-50
Q3(X)E-75
Q3(X)E-125
Q3/4(X)E-100
LIMIT CONTROL FOR:
SP
ADE CONNECTORS
INSULA
TING COVER
LIMIT
LIMIT
Q4(X)E-75
All other units use a fan control-type limit shown in fig-
ure 5. It is used to protect the unit from high tempera-
tures. The blower limit is a resistive-type bimetal SPST
automatic resetting switch. This control does not con-
tain a fan control. The control is factory preset and is
not adjustable. See table 3.
PRIMARY LIMIT TEMPERATURES
Series
Series
TABLE 3
UNIT MODEL NO. TEMP. RISE TEMP. FALL
G20RQ2/3(X)E–50
G20RQ3(X)E–75 Series
Series
230
°
F + 5
°
F 200
°
F + 8
°
F
G20RQ3/4(X)E–100
G20RQ5(X)E–100 Series
Series
G20RQ3(X)E–125
G20RQ4/5(X)E–125
G20RQ4/5(X)E–150
Series
190
°
F + 10
°
F –5
°
F
160
°
F + 10
°
F
220
°
F + 10
°
F 250
°
F + 6
°
F
150
°
F + 15
°
F
180
°
F + 15
°
F
150
°
F + 15
°
F
180
°
F + 15
°
F
G20RQ4(X)E–75 Series
FIGURE 5
HONEYWELL LIMIT CONTROL FOR:
LIMIT SETTING
POINTER
FIXED STOP
G20RQ5(X)E–100
G20RQ4/5(X)E–12
5
G20RQ4/5(X)E–150
NOTE: This control
is actuated by a bi-met-
al coil and does not
contain a fan contol.
NOTE: Do not attempt
to adjust this limit.