Section 658-109-17 - Electrical Equipment, Required Control Switches1. Thermal Electric Switches. A thermal cut-off switch shall be wired into the burner circuit to shut off the burner in the event of a fire at the unit. The switch shall be placed at the highest point directly above the unit to be fired with the thermal element pointed downwards and shall 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 shall 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. A. On multi-unit installations the emergency and thermal electrical switches shall 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. Click here to view Image
2.Service SwitchA. A service disconnect switch for control of the burner while observing the flame shall be placed at the unit, within arm's reach of the technician.3.Emergency Switch(es)A. 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.B. An emergency switch shall not be placed outside of any building. If conditions are encountered preventing strict adherence to this standard, a Modification of Standards must be requested from the Board. (See Chapter 8, Modification of Standards)C. Safety and limiting controls shall not be used to manually start and stop the burner by manual manipulation of the controls, except when permitted by the control manufacturer's installation and operation instructions for testing.D. On commercial and industrial equipment, the emergency switch shall be installed in accordance with Figure 23(c) on multi-unit installations. The requirements of Section 17(1)(A) of this chapter shall not apply to one or two-story residences. (1) On multi-unit installations, the emergency shut-off switch shall be placed at the outside entrance of the room containing the appliances. The emergency switches and the thermal cut-off switches shall 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 shall also apply if there are two or more appliance rooms in the same building connected to a common fuel supply system. NOTE: For Primary Safety Controls, Required Programming and Timings for Burners, refer to ASME CSD-1.
4.Controls Containing MercuryA. Thermostats containing mercury must be disposed of according to all Federal and State Regulations. (Refer to Title 38, Section 1663 and check with your local supplier)02- 658 C.M.R. ch. 109, § 17