LAARS NeoTherm LC NTV1700 - Install and Operating Manual - Manual (Page 34)

LAARS Heating Systems Page 30
Section 7
ELECTRICAL CONNECTIONS
WARNING
The NeoTherm LC 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 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 included in
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.
Note - All internal electrical components have been
prewired. No attempt should be made to connect
electrical wires to any other locations except the
terminal blocks.
The wiring connections are shown in Figures 19 and 21 .
Note - Do not make and break the line voltage to the
NeoTherm LC as a signal to call for heat.
On a system operating as a Lead/Lag installation -
A “call for heat/ end call for heat” must be connected
to the Primary TT or Interlock terminals (terminals 5
and 6 on TB7) on the controller which is acting as the
Lead/Lag master.
On a boiler operating individually -
A “call for heat/ end call for heat” must be connected
to the Primary Thermostat terminals (terminals 5
and 6 on TB7). Any jumper to the System terminals
(terminals 3 and 4 on TB6) must be removed. For
details, see Section 9.
Some NeoTherm LC components are designed to
have constant voltage during normal operation. If
the NeoTherm LC’s supply voltage is toggled as
a call for heat signal, premature failure of these
components may result.
The NeoTherm LC does not recognize 4 mA as a signal
to shut off. If the call for heat is not connected between
the field interlock terminals, NeoTherm LC will remain in
low fire when it sees 4 mA as a modulating signal.
Caution
The supply voltage to the NeoTherm LC must not
be disengaged, except for service or isolation, or
unless otherwise instructed by procedures outlined
in this manual. To signal a call for heat, use the
correct terminals as instructed in Section 9.
7.1 Main Power
For the convenience of the installer, a junction box
has been placed at the rear of the boiler (internal)
for power connections. These connections include
three pre-stripped wires (black, white and green) for
power connections.
For Model 1000 use a single 120-volt 15 Amp fused
supply. For Model 1700 use a single 120-volt 30
Amp fused supply.
7.2 Pump Connections
The NeoTherm LC energizes the appropriate pump
contacts when it receives a call for heat or domestic
hot water. Once the call for heat or DHW is satisfied,
the pump will remain on for the defined pump
overrun time.
Note - The contacts for the System and DHW
pumps are dry contacts. Appropriate voltage must
be supplied to the System and DHW pumps for
proper operation.
The Boiler pump is controlled in two different ways,
depending on the NeoTherm LC model:
• On NeoTherm LC 1000 units the appliance will
supply 120V single-phase power to the Boiler
pump. The current supplied by this source cannot
exceed 7.4 FLA. If more current is required, an
additional relay/pump contactor must be installed.
Wire the relay so it is energized from the contacts
on the boiler to allow the pump to be turned on
and off with the demand.
• On NeoTherm LC 1700 units the appliance
will include a dry contact to operate the Boiler
pump. The current from an alternate power
source through this contact cannot exceed 7.4
FLA at 120V. If more current is required, then an
additional relay/pump contactor must be installed
and controlled by the boiler pump dry contacts.