Brochure

4
6-170.9
DESIGN FEATURES
Figure 4.1 - Factory Mounted Standard Features
➈ High Limit Switches
One limit control is mounted in the air stream and will shut off the
gas supply in the event of overheating. The other limit control is
mounted on the power exhauster housing and will shut off the gas
supply in the event of overheating flue gas temperatures.
➉ Condensate Drain Overflow Switch
Shuts down gas controls if condensate is not properly draining
from the unit.
Gas Pipe Connection
Easy access to factory installed gas pipe connection stubbed to
outside of unit casing.
Condensate Drain Connection
Easy access to factory installed condensate drain pipe connection
stubbed to outside of unit casing.
Combustion Air Inlet Pipe Connection
Simple connection for combustion air inlet piping.
Vent Pipe Connection
Simple Fernco
®
rubber boot connection for PVC vent system.
Fan Guard (Standard for PTC Models)
Propeller units may be equiped with an optional finger proof fan
guard (standard on size 110 and smaller) for added protection. If
ordered, the finger proof fan guard is installed at the factory in place
of the standard fan guard.
Contractor Convenience Package
External junction box features simple connection of supply power
wiring internally, thermostat wiring to terminals externally, an
On/Off switch, a single 115V outlet for connection of an external
condensate pump, and status indicator lights to display the
operational state of the unit.
Horizontal Air Deflector Blades
Factory mounted on the discharge of the unit, the blades can
be adjusted to provide horizontal (up and down) delivery control of
the heated air. Vertical deflector blades are available as a field
installed accessory.
Blower Motor (Standard for BTC Models)
Blower motors smaller than 3 HP are factory installed on the blower
housing. Motors 3 HP and above ship loose for field installation to
prevent damage during shipment. The blower motor is supplied with
an adjustable sheave that can be used to increase/decrease the
blower RPM, and the blower motor can be provided in a variety of
supply voltages and motor horsepowers.
Blower Enclosure (OPT for BTC Models)
Filter Rack (OPT for BTC Models)
Provides filtration of air to be heated. Must include Blower
Enclosure accessory.
➀ Power Exhauster
All units are supplied with a round vent pipe and combustion air
inlet pipe connections.
➁ Pressure Switch
An automatic reset vent pressure switch is supplied on all units
and is designed to prevent operation of the main burner in the
event there is restricted venting of flue products. This restriction
may occur due to an improper vent diameter, long vent runs,
un-approved vent terminal, high winds, high negative pressure
within space, etc. After the cause of the restriction has been
corrected, the pressure switch will reset automatically.
➂ Control Step Down Transformer
The control step down transformer is located in the electrical
junction box. The transformer is used to step down from 115V
to 24V for the gas controls, fan delay relay, field supplied motor
starter, etc. An additional field installed transformer is required if
the supply voltage is 208V, 230V, 460V, or 575V. To determine
the control transformer supplied as well as any required
accessory transformers, refer to Table 10.1.
➃ Integrated Direct Spark Control Board
The integrated direct spark ignition control combines all furnace
control functions. The integrated board provides digital control
of the air mover, inducer, ignition, gas valve and flame sense
as well as monitoring the safety circuit at all times. The board
includes LED diagnostics for trouble shooting and a fused
power supply. Ignition control is 100% shut-off with continuous
retry.
➄ Flame Sensor
Remote flame sensor verifies ignition of all burners, monitors
the flame signal and communicates with the integrated circuit
board.
➅ Single Stage Gas Valve
The main gas valve is factory installed on the unit heater gas
train. The main gas valve provides regulator, main gas, and
manual shutoff functions. The valve is redundant and provides
100% shut off.
➆ Flame Roll Out Switch (size 110 and smaller only) (hidden)
Flame roll out switches are mounted near the burners and will
shut off the gas supply in the event of an unsafe flame roll out
condition.
➇ Direct Spark Igniter
Provides spark for direct ignition of the burners.
14
15
16
17
18
19
20
12
13
11
➄
➀
➃
➉
➅
➁
➂
➈
1 2
11
15
16
13
14
➇
17
18
19
20
Model PTC Model BTC