Nortron B SERIES Installation And Operating Instructions Manual - page 3
GENERAL REQUIREMENTS AND SPECIFICATIONS
(CONT’D)
3
10” x 8” (254 mm x 203 mm) BLOWER
SPEED
FLOW
RATE
STATIC PRESSURE
(INCHES OF WATER COLUMN)
0.2
0.3
0.4
0.5
0.6
LOW****
CFM
L/s
756
357
749
353
740
349
729
344
713
337
MED-LOW
CFM
L/s
1035
488
1018
480
997
470
971
458
935
441
MED-HIGH
CFM
L/s
1177
556
1157
546
1132
534
1102
520
1063
502
HIGH
CFM
L/s
1301
614
1276
602
1247
588
1207
569
1145
540
12” x 8” (304 x 203 mm) BLOWER
†
SPEED
FLOW
RATE
STATIC PRESSURE
(INCHES OF WATER COLUMN)
0.2
0.3
0.4
0.5
0.6
LOW****
CFM
L/s
727
343
699
330
667
315
636
300
606
286
MED-LOW****
CFM
L/s
912
431
897
423
878
414
853
402
823
388
MED-HIGH
CFM
L/s
1216
574
1200
566
1181
557
1157
546
1129
533
HIGH
CFM
L/s
1640
774
1601
755
1558
735
1513
714
1466
692
240 VOLTS – SINGLE PHASE
TEMPERATURE RISE @0. 20” W. C.
MODEL NO. KW
BTUH AMPS INCL. MOTOR
HP
BLOWER
°C
°F
*SPEED
RPM
21B10M
10
34120
46
1/3
10” x 8”
(254 mm x 203 mm)
21
70
LOW
663
21B15M
15
51180
67
1/3
24
75
MED-LOW
814
21B18M**
18
61420
77
1/3
27
81
MED-LOW
814
21B20M**
20
68240
86
1/3
33
91
MED-LOW
814
21B25M**
25
85300
107
1/3
37
99
MED-LOW
814
21B27MS***
†
27
92130
116
3/4
12” x 8”
(304 mm x 203 mm)
36
97
MED-HIGH
707
208 VOLTS – THREE-PHASE
83B13
13.5 46060
42
1/3
10” x 8”
(254 mm x 203 mm)
21
70
MED
960
83B24
24
81890
70
1/3
35
95
MED
960
83B27
27
92130
78
1/3
39
102
MED
960
SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE.
WARNING:
*FACTORY SETTINGS.
**21B18M, 21B20M and 21B25M must NOT be setup to run continuously at LOW speed as it will cause overheating conditions. These
models are certified to run only at HIGH, MED-HIGH and MED-LOW speeds.
***21B27MS must NOT be setup to run continuously at LOW or MED-LOW speeds, as it will cause overheating conditions. This model
is certified to run only at HIGH and MED-HIGH speeds.
****These speeds can only be run with heater off, for cooling/ventilation purposes only.
†
21B27MS has built-in noise-absorption components to run quietly during continuous or regular cycle modes.
OPERATING OPTIONS
The furnace is shipped from the factory in a “Standard Heating Mode”
(all switches are in the Down position). When the thermostat calls for
heat, the automatic controls will be activated and the furnace turned “ON”.
The blower will run at low speed as the furnace heats up and will
automatically switch to a higher speed when additional elements
are activated by the time delay relays.
The timing of this blower speed change will depend on the size of
the furnace (10 kW and 13.5 kW models do not change speed),
and whether C
OLD
or M
ILD
is selected on the SEASON SELECT
switch.
You may, however, change from the Standard Heating Mode by
using the controls built into your furnace.
LOW SPEED
SEASON SELECT
O
N
M
ILD
C
OLD
O
N
–
Some homeowners prefer the blower to run at low speed to
more evenly distribute air in the house. In this position, the
blower will run continuously on low and automatically
change to a higher speed when heating elements are
turned on by the thermostat.
O
FF
– The blower motor will operate in the standard heating
mode, controlled by the thermostat.
M
ILD
–
During spring and fall, you may not require full heating
capacity to maintain a comfortable temperature. In this
position, approximately half of the elements are “off-line”
and will not be energized when the thermostat calls for heat.
C
OLD
– All elements are “on-line” and controlled by the thermostat.
NOTE:
If outdoor or two-stage thermostat is used, switch MUST
be in M
ILD
position at all times.
O
FF
(
NOT INCLUDED IN MODELS
21B10M
AND
83B13)