Direct Gas Make-Up Air
27
High/Low Gas Pressure Switch(es)
An optional high and/or low gas pressure switch(es) may
have been provided with the unit. The location of these
switches is shown in the
Pre-Start-Up: Direct Gas-
Fired Heating, Gas Train Identification
section in this
Installation, Operation and Maintenance Manual. The
high gas pressure switch will automatically shutdown
and lockout burner operation if the manifold gas
pressure is too high. The low gas pressure switch will
automatically shutdown and lockout burner operation
if the inlet gas pressure is too low. Both gas pressure
switches will require a manual reset. The manual reset
is a push button located on the top of the pressure
switches.
The pressure thresholds are factory set but can be
adjusted if necessary.
Maxitrol SC Series Amplifier
This system requires that an analog control signal be
provided to control the burner firing rate. This signal
can be a 0-10 VDC or a 4-20 mA control signal and is
provided by others unless the unit has been outfitted
with a microprocessor controller. If this is the case,
reference the supplemental
Microprocessor Controller
for Make-Up Air Reference Guide
for more information
.
Typically the SC Series amplifier is wired to an owner-
supplied Building Management System which provides
the signal to vary the burner firing rate.
Note: The SC Series amplifier also limits the minimum
and maximum discharge air temperatures. Reference
the unit specific wiring diagram and Maxitrol data sheets
included in the packet for further reference.
Pre-Start: Direct Gas-Fired Heating
Accessory Identification
Model No.
High Pressure
Honeywell C6097B1028
Low Pressure
Honeywell C6097A1012
Typical Gas Pressure Switch
Manual reset
Maxitrol SC Series
2-10 VDC or 4-20 mA signal in
[terminals 5 (-) and 6 (+)]
All 3 DIP switches must be positioned
to the ON or OFF position based on
signal being sent.
J1 jumper = No jumper (required)
J2 jumper = 1-2 (suggested position)
J3 jumper = 2-3 (required)
Temperature Control Identification
(continued)
UV Scanner
The optional UV scanner is a flame sensing
device that can be used in lieu of a flame rod.
The UV eye senses the flame by detecting
the ultraviolet light produced by the flame.
A special spark generator and rectification
amplifier card are required with the use of this
option.
