Access To Connection Block; Main Supply Connection - UTICA BOILERS MAH-125 Installation, Operation And Maintenance Manual

!
DANGER
Electrocution Hazard! HIGH VOLTAGE - Connections
in terminal block M1 are high voltage (120V / 60Hz).
Before making connections, verify appliance is
disconnected from power supply. Respect the input
polarity on terminal block M1: L (LINE) - N (NEUTRAL).
Failure to follow these instructions WILL result in death
or serious injury.

8.4 Access To Connection Block

1.
Ensure there is no line voltage at boiler.
2.
Unscrew two screws located under front panel. Remove
front cover.
3.
Guide controller or thermostat wire through round
grommet(s) on right side of boiler's bottom plate right.
4.
Tilt control box forward by opening holding clips located
on left side of boiler.
5.
Expose M1 and M2 terminal blocks by removing screw
from plastic cover on left. See Figure 8-3.
6.
Remove plastic from channel in plastic cover. Run wires
through new opening.
7.
Connect wires to appropriate terminals on connection
block.
8.
Tilt control box back to original position. Ensure clip on
left side is fully engaged.
9.
Replace front cover and screws under front panel.
10.
Turn power to boiler on.
Various thermostats and controllers can be connected to
standard control PCB.

8.5 Main Supply Connection

Main supply is connected to terminal block M1 which is high
voltage (120V / 60Hz).
Fuses, 3.15 A, are incorporated in the power supply terminal
block. To check or replace fuse pull out black fuse carrier.
TERMINAL BLOCK M1
(L) = Live (brown)
(N) = Neutral (light blue).
= Ground (yellow-green).
(1) (2) = contact for 120V Room Thermostat.
Place jumper back on terminals 1-2 of boiler terminal block
M1 if room thermostat is not used or if Remote Control is
not installed.
8 - ELECTRICAL CONNECTIONS
FIGURE 8-2 Terminal Block Locations
FIGURE 8-3 Terminal Plastic Cover with Knockouts
TERMINAL BLOCK M2
Terminals 1 - 2: bus connection of programmable room unit
(supplied as accessory)
Terminals 4 - 5: outdoor temperature sensor connection
(supplied as accessory)
Terminal 3 : not used.
Terminals 6 - 7 - 8: see section 8.6.
Terminals 9 - 10: Indirect storage tank sensor connection
for Utica Boiler MAH-125 & 165 model.
34
Fuse Holders (2)
Remove
New Opening
240011941 REV B, [03/31/2018]