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P/N HN-IOM-1 82-0331 Copyright 2009 Mestek, Inc.
Finned copper tube gas boilers & water heaters – Control manual
1 Stand-alone boiler . . . . . . . . . . . . . . . . . . . . . . page 6
Provide an external contact connected across J12A HEAT DEMAND terminals
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to start the boiler. (A MEMBER boiler in a network can also be activated by closing
the circuit across HEAT DEMAND.)
The boiler can operate based on its SUPPLY temperature, or can be operated by re-
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mote control from a 4-20mA source. And setpoint temperature can be controlled
locally or by 4-20mA signal from a remote source.
The boiler’s T1/T2 terminals can be used to operate the boiler as two-stage (fired
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at minimum input or maximum input).
The AA terminals can be used to fire the boiler as ON/OFF at maximum input.
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2 Multiple boilers: HeatNet modulation . . . page 8
The HeatNet control can control up to (16) boilers using built-in software and
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hardware.
Boilers come standard with HeatNet communications capability, and require only
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RJ45 HeatNet cables (or shielded wires) to connect between them.
The header water temperature setpoint can be set by the master boiler or by a
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4-20ma input from an external controller.
Member boilers can override master boiler control if they receive a contact closure
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on the HEAT DEMAND terminals or the AA high fire terminals. In addition, the
controls can be set up to allow priority override by a remote 4-20mA source.
3 Multiple boilers: BMS operation . . . . . . . . page 13
PREFERRED —
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Combined BMS/HeatNet operation
— This method uses
the HeatNet control’s built-in communications capabilities to accept MODBUS
protocol inputs from a building management system. The master boiler control
sequences and modulates the boiler network to accomplish the demands from the
building management system.
ALTERNATE —
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Direct BMS control of all boilers
— Each boiler can be op-
erated directly by the BMS (each boiler will require an optional plug-in protoces-
sor if using BACnet or LonWorks).
Boiler setup is essentially the same as for method 2, with the exception that each
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boiler must be assigned both a HeatNet network address and an address for the
MODBUS interface.
An optional plug-in protocessor is required to interface with systems using BACnet
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or LonWorks protocol.
The master boiler will take control and regulate the boiler network if signal from
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the BMS is lost or times out.
4 External 4-20ma control . . . . . . . . . . . . . . . . page 15
4-20mA/HeatNet combined operation — The master boiler can receive the
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4-20mA modulation signal and control the other boilers.
RBI
Futera
III
/XLF/FUSION
-Series boilers — HeatNet
TM
control
Futera
HeatNet
Electrical enclosure
