Page 31
N
EO
T
HERM
Boilers and Water Heaters
Section 7 -
INSTALLATION AND WIRING
7.1 Installation Warnings
7.2 Main Power Connections
Connect a 15A fused, 120-volt supply to the main power
switch. (The hot leg is connected directly to the switch.)
The neutral leg is connected directly to the white wire. The
ground wire can be connected to the grounding lug on the
control panel. (See Figure 27.)
7.3 Pump Connections and Operation
The controller in the NeoTherm energizes the pump contacts
when it receives a call for heat. Once the call for heat is
satisfied, the pump will remain on for the defined pump
overrun time.
The Boiler Pump terminals (TB5 - max 7.4 FLA) are fed
by 120V (violet wire) internally from the main power feed.
The System and DHW contacts are dry contacts. Appropriate
voltage must be supplied to the System and DHW pumps for
proper operation.
The System pump connections are located on terminal block
5 (TB5) in the control panel. (See Figure 27.) The System
pump contacts are rated for 120Vac, 7.4 Amps. To use the
contacts, power must be supplied on one terminal with the
other terminal wired to the pump or a relay controlling the
pump.
The DHW pump connections are located on terminal block
5 (TB5) in the control panel and are rated for 120Vac, 7.4
Amps. To use the contacts, power must be supplied on one
terminal, and the other terminal wired to the pump or a relay
controlling the pump.
Additional 120VAC circuits may be required for the pumps.
WARNING
The appliance must be electrically grounded in
accordance with the requirements of the authority
having jurisdiction or, in the absence of such
requirements, with the latest edition of the National
Electrical Code, ANSI/NFPA 70, in the U.S. and with
the latest edition of CSA C22.1 Canadian Electrical
Code, Part 1, in Canada. Do not rely on the gas or
water piping to ground the metal parts of the boiler.
Plastic pipe or dielectric unions may isolate the boiler
electrically. Service and maintenance personnel, who
work on or around the boiler, may be standing on wet
floors and could be electrocuted by an ungrounded
boiler. Electrocution can result in severe injury or
death.
Single pole switches, including those of safety
controls and protective devices, must not be wired in
a grounded line.
All electrical connections are made on the terminal
blocks that are located inside the control panel.
Wiring connections are shown in Figure 34.
All internal electrical components have been
prewired. No attempt should be made to connect
electrical wires to any other location except the
terminal blocks.
Caution
The supply voltage to the NeoTherm unit must not
be disconnected, except for service or isolation, or
unless otherwise instructed by procedures outlined
in this manual. To signal a call for heat, use the 24V
field interlock, as shown in the wiring diagram.
DO NOT MAKE AND BREAK THE LINE VOLTAGE
TO THE NEOTHERM UNIT TO SIGNAL A CALL
FOR HEAT. A call for heat/ end call for heat MUST
be connected to the field interlock terminals. Some
NeoTherm components are designed to have
constant voltage during normal operation. If the
NeoTherm’s supply voltage is toggled as a call for
heat signal, premature failure of these components
may result.
The NeoTherm unit does not recognize 4mA as a
signal to shut off. If the call for heat is not connected
between the field interlock terminals, the NeoTherm
will remain in low fire when it sees 4mA as a
modulating signal.
7.4 Hydronic Heating Using External
Modulation Control -
About External Control -
When the NeoTherm is used for hydronic heating with
external modulation control, a call for heat must be
supplied to the “T-T or Interlock” terminal. Once the call
is supplied the control starts the Boiler and System pumps
and begins the ignition process. Once in Run, the NeoTherm
monitors the flame signal, call for heat, safeties, and
water temperatures. The boiler setpoint is used to limit the
maximum water temperature leaving the boiler only. The
modulation rate is controlled by a 4-20mA signal supplied
by an external control. (This can also be 0-10Vdc using a
converter - Laars part number CA006100.) When setting up
a system using an external control, take care to set Anti-Short
Cycle feature to prevent “hunting “ and possible premature
component failure.
Summary of Contents for NTV
Page 4: ...LAARS Heating Systems...
Page 11: ...Page 7 NEOTHERM Boilers and Water Heaters...
Page 24: ...Page 20 LAARS Heating Systems Figure 16 Hydronic Piping Single Boiler Zoning with Circulators...
Page 84: ...Page 80 LAARS Heating Systems Parts Illustration 1 Jacket Components...
Page 86: ...Page 82 LAARS Heating Systems Parts Illustration 4 Internal Components Sizes 750 850...
Page 88: ...Page 84 LAARS Heating Systems Parts Illustration 6 Gas Train Components Sizes 600 850...
Page 91: ...Page 87 NEOTHERM Boilers and Water Heaters Notes...
