13.8.1
Code Compliance; General Requirements
The following requirements must be met with respect to the
electrical wiring and equipment used in connection with propane or natural gas
burning equipment:
1. The electrical
wiring and equipment used must be installed in accordance with NFPA
70;
2. Safety control circuits must
be two-wire, one side grounded, having a nominal voltage not exceeding 150
Volts. A safety control or protective device must be connected so as to
interrupt the ungrounded conductor; and
3. The control circuit must be connected to a
power supply branch circuit fused at not more than the value appropriate for
the rating of any control or device included in the circuit.
4. Whenever a furnace, direct-fired hot water
heater, or boiler is installed, each unit must have its own dedicated
electrical circuit.
13.8.2
Emergency Switch
13.8.2.1 For central heating equipment and
water heating appliances where the interruption of an electrical circuit will
arrest the combustion process, an identified emergency shutdown switch must be
placed outside of and adjacent to the entrance of the room where the appliance
is located.
13.8.2.2 An emergency
switch shall not be placed outside of any building.
13.8.2.3 If the entrance to the boiler room
is only accessible from the outside, the emergency switch may be placed at the
inside not more than one foot beyond the door opening.
13.8.2.4 On multi-unit installations of
commercial and industrial equipment, the emergency switch must be installed in
accordance with Figure 13-1.
13.8.2.5 On multi-unit installations, in
other than one- and two-family residences, the emergency shut-off switch must
be placed at the outside entrance of the room containing the appliances. The
emergency switch must be wired so that, if the emergency switch is opened, all
central heating equipment and water heating appliances (within that room) where
the interruption of an electrical circuit will arrest the combustion process
will be rendered inoperable. Where there are other (new or existing) multi-unit
appliance rooms in the same building, those rooms must also be made compliant
with this requirement.
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13.8.3
Service Switch
For central heating equipment and water heating appliances
where the interruption of an electrical circuit will arrest the combustion
process, a service disconnect switch for control of the burner while observing
the flame must be placed at the unit, within three (3) feet of the
burner.
13.8.4
Thermal
Cut-Off Switches
13.8.4.1 For central
heating equipment and water heating appliances where the interruption of an
electrical circuit will arrest the combustion process, a thermal cut-off switch
must be wired into the burner circuit to shut off the burner in the event of a
fire at the unit. The switch must be placed at the highest point directly above
the unit to be fired with the thermal element pointed downwards, and must be
placed on the bottom of the floor joist or stringer at the front of the unit.
In no case shall it be lower than the point where the flue connector enters the
chimney. The switch must be wired to shut off the burner, circulating fan,
forced or induced draft fan and any electrically-operated gas valves. A thermal
electric switch is required for each electrically-powered gas-fired unit in a
multi-appliance installation.
13.8.4.2 On multi-unit installations other
than one- and two-family residences the thermal electrical switches must be
wired in series through individual unit relays so that, if one switch is
opened, all equipment will be rendered inoperable.
13.8.5
Controls Containing
Mercury
Thermostats containing mercury must be disposed of according
to all federal and state regulations. (Refer to
38 M.R.S.
§1663 and check with your local
supplier.)
