LAARS Mascot LX MLXC 175 MBH - Install and Operating Manual - Manual (Page 31)

Mascot LX Boilers and Water Heaters Page 27
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 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.
NOTE: 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
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and
dangerous operation. Verify proper operation after
servicing
CAUTION
Mascot LX supply voltage 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 24V DC field-interlock,
as shown in the wiring diagram(s).
7.1 Main Power
Plug power cord into a non-switched 115V electrical
outlet with 15A circuit protection. FLA is 2A. There
is an internal 10A breaker to protect internal system
components.
7.2 Pump Connections
Mascot LXC energizes boiler pump (opens 3-way
valve), and system pump upon a demand for Central
Heat. Mascot LXH energizes boiler pump and system
pump upon a central heat demand
The combined load for all pumps must not exceed
5 amps. In some installations, a pump relay may be
required.
7.3 24Vac Transformer with Circuit Breaker
24Vac is supplied by a transformer mounted behind the
lower door. All 24Vac power is supplied through a 2A
circuit breaker located behind lower door.
7.4 Central Heat - Call for Heat
Connect the Call for Heat to terminals #5 and #6
(connections labeled "T-T or interlock").
7.5 Outdoor Air Temperature Sensor
Connect the outdoor air temperature sensor to
connections labeled "Outdoor sensor." The outdoor air
temperature sensor is used for warm weather shutdown
and outdoor reset. If an outdoor sensor is not installed,
the CH setpoint of the boiler is limited to 140°F.
7.6 Domestic Hot Water Connection
For indirect water heater, connect aquastat for remote
sensor to terminals #7 & #8 or domestic hot water
sensor to terminals #9 & #10 (see Figure 21 ).
Domestic Hot Water Sensor PN is E2337501
7.7 System Sensor
Connect the system sensor to connections labeled
"system sensor" on lead boiler only. #3 and #4
7.8 External Control Connections
If the unit is being controlled by an external 0-10VDC
signal, connect this to terminals 11 and 12. When
making the connections, follow the polarity designations
shown on the label. A "dry" alarm contact is located on
terminals 10 and 11 at high voltage panel (backside).
Note: The 0-10VDC signal may be to send a modulation
signal, or a temperature setpoint signal to the boilers
from a building management program (See Section 9).