02-658 C.M.R. ch. 8, § 15 - Electrical Equipment, Required Control Switches

8.15.1 Thermal Cut-Off Switches

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 remote oil pump that is not an integral part of the burner. A thermal electric switch is required for each oil-fired unit in a multi-appliance installation.

8.15.1.1 On multi-unit installations, the emergency and 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 whenever the "EMERGENCY" switch is opened.

8.15.1.2 All remote pump sets must have a thermal cut-out switch installed as follows:

1. Maximum of three (3) feet above pump set;

2. The element must be pointed downwards; and

3. The switch must be supported in accordance with NFPA 70.

8.15.2 Service Switch

A service disconnect switch for control of the burner while observing the flame must be placed at the unit, within arm's reach of the technician.

8.15.3 Emergency Switch

8.15.3.1 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. An emergency switch shall not be placed outside of any building.

8.15.3.2 On commercial and industrial equipment, the emergency switch must be installed in accordance with Figure 8-4 on multi-unit installations. The requirements of Section 8.15.1.1 do not apply to one- or two-family residences.

8.15.3.2.1 On multi-unit installations, the emergency shut-off switch must be placed at the outside entrance of the room containing the appliances. The emergency switches and the thermal cutoff switches must be wired in series through individual unit relays so that, if the emergency switch is opened, all heating equipment in the room and the remote pump set will be rendered inoperable. This application also applies if there are two or more appliance rooms in the same building that are connected to a common fuel supply system.

[NOTE: For Primary Safety Controls, Required Programming and Timings for Burners, refer to ASME CSD-1.]

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8.15.4 Controls Containing Mercury

Thermostats containing mercury must be disposed of in accordance with all federal and State Regulations. (Refer to 38 M.R.S. § 1663 and check with your local supplier)

Notes

02-658 C.M.R. ch. 8, § 15