Nortron D SERIES Installation And Operating Instructions Manual - page 3
GENERAL REQUIREMENTS AND SPECIFICATIONS
(
CONT
’
D
)
*FACTORY SETTINGS.
SUBJECT TO CHANGE WITHOUT NOTICE.
240 VOLTS – SINGLE PHASE
TEMP. RISE @ 0.20 IN. W.C.
MODEL NO.
KW
BTUH
AMPS INCL. MOTOR
HP
BLOWER
°C
°F
*SPEED
RPM
21D10
10
34120
46
1/3
10” x 8”
(254 mm x 203 mm)
21
70
MED-LOW
814
21D15
15
51180
67
1/3
24
25
MED-LOW
814
21D18
18
61420
77
1/3
27
81
MED-LOW
814
21D20
20
68240
86
1/3
33
91
MED-LOW
814
21D23
22.5
76842
94
1/3
36
97
MED-LOW
814
21D25
25
85003
107
1/3
37
99
MED-LOW
814
21D27
27
92130
116
3/4
12” x 8”
(304 mm x 203 mm)
36
97
MED-HI
707
OPERATING OPTIONS
The furnace is shipped from the factory in a “Standard Heating
Mode” (narrow switches in the Down position, wide switch in the
Middle — or Off — position). When the thermostat calls for heat,
the automatic controls will be activated and the furnace turns
“ON”.
The blower will run at low speed or higher speed (as selected by
Speed Selector switch).
As the furnace heats up, it automatically switches to a medium
speed when additional elements are activated by the electronic
control, if it was initially set to run at low speed. The timing of this
blower speed change will depend on whether “Cold” or “Mild” is
selected on the Season Select switch.
You may, however, change from the Standard Heating Mode by
using the controls built into your furnace.
S
PEED
S
ELECTOR
S
EASON
S
ELECT
C
ONTINUOUS
S
PEED
H
IGH
M
ILD
C
OLD
L
OW
H
EAT
O
FF
N
O
H
EAT
The Speed Selector switch is used to
control the fan speed. It is also used in
conjunction with the Continuous Speed
switch.
“Low” – The blower motor will operate at
low speed.
“High” – The blower motor will operate at
a higher speed.
During spring or fall, you may require less
rapid response when the thermostat calls
for heat.
When “Mild” is selected, it takes more time
to bring all the elements online.
When “Cold” is selected, the heating
elements come online faster.
When the “Low Heat” switch is selected
only one element will offer continuous
warmth.
When “No Heat” is selected the blower will
run continuously at either Low or High
speed as selected by the Speed Selector
switch.
When “OFF” is selected the blower is not
engaged.
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
WARNING:
**This speed can only be run with heater off, for cooling/ventilation purposes only.
3
L
OW