Installation Guide

38
UPRIGHT INSTALLATIONS
Depending on the installation and/or customer preference, differing filter arrangements can be applied. Filters can be installed in the
central return register or a side panel external filter rack kit (upflows). As an alternative a media air filter or electronic air cleaner can
be used as the requested filter.
The following figure shows possible filter locations.
FILTER
AIR FLOW
CENTRAL
RETURN
GRILLE
FILTER
SIDE RETURN
EXTERNAL FILTER
RACK KIT
(EITHER SIDE)
Possible Upright Upflow
Figure 42
F
I
L
T
E
R
AIR FLOW
CENTRAL
RETURN
GRILLE
RETURN
DUCT
F
IL
TE
R
FILTER
SUPPORT
BRACKET
(Field Supplied)
FILTER
ACCESS
DOOR
Possible Upright Counterflow
Filter Locations
Figure 43
HORIZONTAL INSTALLATIONS
Filters must be installed in either the central return register or in the return air duct work.
S TARTUP P ROCEDURE & A DJUSTMENT
Furnace must have a 115 VAC power supply properly connected and
grounded. Proper polarity must be maintained for correct opera-
tion. In addition to the following start-up and adjustment items,
refer to further information in Operational Checks section.
Call for heat, thermostat energizes W1 on the furnace control
board (W2 input is ignored).
After a successful Light Off Sequence and expiration of the
Ignition Stabilization Period:
• The furnace control board adjusts the firing rate to 35%
(low fire rate).
• After 2 minutes, the furnace control board increases the
firing rate to 57% at a rate of 1% per second.
• After 10 total minutes, the furnace control board increases
the firing rate to 78% at a rate of 1% per second.
• After 20 total minutes, the furnace control board increases
to 100% at a rate of 1% per second for the remainder of the call for heat.
• The circulator fan is adjusted to the appropriate CFM, corresponding to the current firing rate.
MIN.
57%
78%
(80%)
100%
IGNITION
UNIT CALL FOR HEAT ENDS
10 MINS.
8 MINS.
2 MINS.
Operation with Conventional 1-Stage Thermostat
(DIP switch selects 1-Stage heat)
Figure 44