LAARS NeoTherm NTV1000 - Install and Operating Manual - Manual (Page 32)

LAARS Heating Systems
Page 28
Section 7
eleCtrICal ConneCtIonS
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 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 unit 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 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 4 mA as a
signal to shut off. If the call for heat is not connected
between the field interlock terminals, NeoTherm will
remain in low fire when it sees 4 mA as a modulating
signal.
Caution
The supply voltage to the NeoTherm 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
Connect a 15 A fused, 120 VAC 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 wire in the junction box. (See Figure
27.)
7.2 Pump Connections
The NeoTherm 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 contact (max 7.4 FLA) is
fed by 120 V internally from the main power feed.
Due to the size of the pumps required to operate
the boiler and system properly, it is likely that the
maximum ratings of the Boiler pump contacts will
be exceeded (120 Volts, 7.4 FLA). In this case, an
additional relay must be installed. The relay may be
energized from the contacts on the boiler to allow
the pumps to be turned on and off with the demand.
The System pump connections are located on
terminal block 5 (5-6 on TB5) in the control panel.
(See Figure 19.) The System pump contacts are rated
for 120 VAC, 7.4 Amps. To use the contacts, power
must be supplied on one terminal with the other
terminal wired to the relay controlling the pump.
The DHW pump connections are located on terminal
block 5 (7-8 on TB5) in the control panel and are
rated for 120 VAC, 7.4 Amps. To use the contacts,
power must be supplied on one terminal, and the
other terminal wired to the relay controlling the
pump.