LAARS EDN Series - Installation, Operation and Maintenance Instructions - Manual (Page 20)

Page 20 LAARS Heating Systems Company
SECTION 5.
Electrical Connections
5.1 Electrical Connections
All electrical wiring must conform to local codes
and/or the latest edition of the National Electric Code
(NEC; NFPA 70) or the Canadian Electric Code, Part
1 (CEC; CSA C22.1). Any applicable local codes must
also be adhered to.
The unit must be electrically grounded in
accordance with the requirements of the authority
having jurisdiction or, in the absence of such
requirement, with the latest edition of the National
Electric Code (NEC; NFPA 70) or the Canadian
Electric Code, Part 1 (CEC; CSA C22.1). Any
applicable local codes must also be adhered to.
Single pole switches, including those of safety
control and protective devices must not be wired in a
grounded line.
All electrical connections are made through
the electrical knockouts on the control panel. The
knockout on the right side of the control panel can be
used to mount a wiring box, if desired.
NOTE: All internal electric components have been
pre-wired. No attempt should be made to connect
electric wires to any other location except the wiring
box as described below.
1. Main power: Connect a fused 120 volt supply
(15 amp) to the main power switch (see
Figure 24) (hot leg is connected directly to
switch). Neutral leg to white wire. Ground wire
can be connected to the grounding screw in the
box or on the switch.
2. For single zone installations: (If external pump is
required, e.g., because of large system pressure
drop) connect room thermostat wires to the red
and white/red wires. Connect circulator (120
volt, 5 amps maximum) between the blue wire
and the white wire (neutral) (see Figure 25). Note
that the blue/white pump wire connects to a dry
T'STAT (T)
GROUND
120 VAC LINE
CIRCULATOR
T'STAT (T)
CIRCULATOR
120 VAC NEUT.
RED
WHT/RED
GRN/YEL
BLK
BLU/WHT
WHT
BLU/WHT
C1
120
VA
C
ROOM T'STAT
Figure 24. Single Zone With Room Thermostat (internal
pump provides system flow).
Figure 25. Single Zone with Added Circulator(s) and
Room Thermostat(s).
RED
WHT/RED
GRN/YEL
BLK
BLU/WHT
WHT
BLU/WHT
T'STAT (T)
GROUND
120 VAC LINE
T'STAT (T)
120 VAC NEUT.
ENDURANCE
FIELD WIRING BOX
ENDURANCE
FIELD WIRING BOX
Figure 26. Multiple Zones Utilizing Four Wire Zone Valves with (Dry) End Switches.
T'STAT (T)
GROUND
120 VAC LINE
CIRCULATOR
T'STAT (T)
CIRCULATOR
120 VAC NEUT.
RED
WHT/RED
GRN/YEL
BLK
BLU/WHT
WHT
BLU/WHT
ZONE THERMOSTATS
TRANSFORMER
120 VAC
C1
120
VA
C
ENDURANCE FIELD
WIRING BOX
contact. The line voltage and pump wire must
be connected per the wiring figures, or the pump
may not be energized.
3. Zone Valves and Thermostats: Install external
24 volt transformer of sufficient V.A. to power
combined load of zone valves. Consult zone
valve manufacturer’s instructions. Connect