User Manual

6
6-189.14
DESIGN FEATURES - MODELS PTP & BTP
Figure 6.1 - Factory Mounted Standard and Optional Features (Model PTP)
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j Power Exhauster (STD)
All PTP series unit heaters are supplied with a round vent
pipe connection.
k Pressure Switch (STD)
An automatic reset vent pressure switch is supplied on
all PTP series unit heaters 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, unapproved 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. See the trouble
shooting section of the installation and service manual for
more information.
l Integrated Direct Spark Control Board (STD)
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.
m Gas Valve - (See Table 18.2)
a) Single Stage Gas Valve - (STD)
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.
b) Two Stage Gas Valve - (OPT)
The two-stage gas valve is factory installed on the unit
heater gas train. The two stage gas valve provides the
regulator, main gas (100% and 50% fire), and manual
shutoff functions. The valve is redundant and provides
100% shut off.
n Control Step Down Transformer - (STD)
The control step down transformer is located in the
electrical junction box. The transformer is used to step down
the supply power (115V, 208V, 230V, 460V, 575V) to 24V for
the gas controls, fan delay relay, field supplied motor starter,
etc. To determine the control transformer supplied as well
as any accessory/field supplied transformers required, refer
to Table 18.1
o Flame Sensor – (hidden, STD)
Remote flame sensor verifies ignition of all burners,
monitors the flame signal and communicates with the
integrated circuit board.
p Direct Spark Igniter - (hidden, STD)
Provides spark for direct ignition of the burners.
q Auto High Limit Switch - (hidden, STD)
The limit control is mounted in the air stream and will shut
off the gas supply in the event of overheating.
r Gas Pipe Connection
Easy access to factory installed gas pipe connection
stubbed to outside of unit casing.
s 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.
s Finger Proof Fan Guard (hidden, OPT for PTP only)
Propeller units may be equipped with an optional finger
proof fan guard for added protection. The finger proof fan
guard is installed at the factory in place of the standard fan
guard.