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MODU-FIRE
®
Forced Draft Gas-Fired Boiler 2500-3000
12
External Interlock
- Use for attachment of an additional field safety device to the boiler control circuit. Closing
this circuit allows the boiler to run. Opening this circuit prevents the boiler from running. This circuit is energized
by the boiler with a 5V potential. Devices connected to these terminals must be rated for 5V.
Outdoor Temp Sensor
– LV7 and LV8 are connected to the outdoor temperature sensor. The temperature
control must be programmed to run an outdoor air schedule. The outdoor air sensor and programming help are
available from the local Harsco Industrial, Patterson-Kelley Representative. This circuit is energized by the boiler
with a 5V potential. The temperature sensor must be a NTC having 12k@25°C.
DHW Stat/Sensor
– LV9 and LV10 are connected to the DHW temperature sensor or thermostat. This circuit is
energized by the boiler with a 5V potential. The temperature sensor must be a NTC having 12k@25°C.
Header Temp Sensor
– LV11 and LV12 are connected to the header temperature sensor. This circuit is
energized by the boiler with a 5V potential. The temperature sensor must be a NTC having 12k@25°C.
DHW Flow Switch
– LV13 is energized by the boiler with a 5V potential. This circuit connects through a flow
switch on the domestic side of a domestic hot water system. The flow switch should close upon flow to provide a
closed circuit back to LV14.
Analog Input
– Remote signal for controlling the boiler. The boiler can be operated in a remote setpoint or a
remote firing rate control mode. Input 0-10VDC signal only. The temperature control must be programmed to run
with the analog input.
MODBUS
®
– LV19 and LV20 are used for connecting a MODBUS
®
building management system. (See the ENVI
®
Control Advanced Users Guide for more information)
Cascade
– LV21 and LV22 are used to connect between boilers that are part of a Master/Member Network. Up to
24 boilers may be connected together. (See the ENVI
®
Control Advanced Users Guide for more information)
3.5 I
NLET
A
IR AND
E
XHAUST
V
ENTING
3.5.1
Applicable Codes & Standards
CODES
United States:
NFPA 54/ANSI Z223.1
National Fuel Gas Code
NFPA/ANSI 211
Chimneys, Fireplaces, Vents and Solid Fuel Burning Appliances
Canada
CAN/CSA B149.1
Installation Codes for Gas Burning Equipment
STANDARDS
UL 1738
Venting Systems for Gas-Burning Appliances, Categories II, III, and IV
These codes and standards contain information for the venting of gas fired appliances, including, but not limited to
vent sizing, location, clearance to combustibles, and safe installation practices. The installation must comply with
both the above Federal Codes and with state, provincial and local codes.
Design and installation of venting systems should be done only by qualified and
knowledgeable venting systems personnel and in accordance with vent system manufacturer’s installation
instructions. Installing a boiler or vent system using improper installation methods or materials can result in
serious injury or death due to fire or asphyxiation.
Summary of Contents for 1004905923
Page 2: ...MODU FIRE Forced Draft Gas Fired Boiler 2500 3000 2 ...
Page 45: ...MODU FIRE Forced Draft Gas Fired Boiler 2500 3000 45 6 1 3 Wiring Schematic ...
Page 48: ...MODU FIRE Forced Draft Gas Fired Boiler 2500 3000 48 6 1 6 Rear Junction Box ...
Page 49: ...MODU FIRE Forced Draft Gas Fired Boiler 2500 3000 49 6 1 7 Customer Connections ...
Page 56: ...MODU FIRE Forced Draft Gas Fired Boiler 2500 3000 56 ...