used in connection with electrical control devices, as compiled by REES, Inc.

Note: Following each word is the reference standard where the definition was located. Also, multiple definitions are displayed to show the diversity of differing opinions.

OPERATING FORCE (NEMA ICS 2-225) - A straight-line force in the designated direction applied to the actuator to cause the switch contacts to snap to the operated position.

PINCH POINT (OSHA 29CFR1910.211 (d)) - Any point other than the point of operation at which it is possible for a part of the body to be caught between the moving parts of a press or auxiliary equipment, or between moving and stationary parts of a press or auxiliary equipment or between the material and moving part or parts of the press or auxiliary equipment..

POINT OF OPERATION (OSHA 29CFR1910.211 (d)) - The area of the press where material is actually positioned and work is being performed during any process such as shearing, punching, forming, or assembling.

POLE (NEMA ICS 1-100.2) - A combination of mating contacts that are normally open, or normally closed, or both..

POSITIVE BREAK - The switch is designed so that the N.C. (Normally closed contact) has a positive mechanical linkage to the operator arm which forces the N.C. contact open. Even if a spring fails, or the N.C. contact hangs up, the mechanical linkage forces the N.C. contact open. Even if the N.C. contact sticks or welds-in, the mechanical linkage forces the N.C. contact open.

POSITIVE TRANSFER - A switch system so designed that the contacts will remain in one state (N.O. or N.C.) until the switch actuator is moved to a "point of no return" and once the contacts start to move they instantly transfer to the opposite state and cannot be teased.

REPEAT (OSHA 29CFR1910.211 (d)) - An unintended or unexpected successive stroke of the press resulting from a malfuction.

RESET (NEMA ICS 1-100.2) - To restore a mechanism, storage, or device to a prescribed state.

SAFTEY BLOCK (OSHA 29CFR1910.211 (d)) - A prop that, when inserted between the upper and lower dies or between the bolster plate and the face of the slide, prevents the slide from falling of its own deadweight.

SLOW MAKE - SLOW BREAK - The rate of change (time and speed) of a contact set moving from one position to another that is dependant upon the operator, that is, if the operator moves slowly then the contacts are transferred slowly. Teasing is possible.

SNAP ACTION (NEMA ICS 1-100.2) - A rapid motion of the contacts from one position to another position, or their return. This action is relatively independant of the rate of travel of the actuator.

SWITCH (UL 508) - A device for opening and closing and for changing the connection of a circuit. A switch is understood to be manually-operated, unless otherwise stated.

SWITCH (SLACK CABLE) (ASME B20.1b) - A device installed to automatically shut off the power supply when the hoisting cable becomes slack or has slack due to an accident or jamming.

TAGOUT DEVICE (OSHA 29CFR1910.147 (b)) - A prominent warning device, such as a tag and a means of attachment, which can be securely fastened to an energy isolating device in accordance with an established procedure, to indicate that the energy isolating device and the equipment being controlled may not be operated until the tagout device is removed.

TWO HAND CONTROL DEVICE (OSHA 29CFR1910.211 (d)) - A two hand trip that further requires concurrent pressure from both hands of the operator during a substantial part of the die-closing portion of the stroke of the press.

TWO HAND TRIP (OSHA 29CFR1910.211 (d)) - A clutch actuating means requiring the concurrent use of both hands of the operator to trip the press.

VOLTAGE, EXTRA-LOW (Can. Elec. Code, Part 1; Sec. 0) - Any voltage up to and including 30 V.

VOLTAGE, LOW (Can. Elec. Code, Part 1; Sec. 0) - Any voltage from 31 to 750 V. inclusive.

VOLTAGE, LOW (UL 491) - A circuit involving a pontential of not more than 30 volts AC and supplied by a primary battery or by a standard Class 2 transformer, or by a combination of transformer and fixed impedance which, as a unit, complies with all of the performance requirements for a Class 2 transformer.

VOLTAGE, HIGH (UL 491) - A circuit involving a pontential of not more than 600 volts and having characteristics in excess of those of a low voltage or an isolated limited secondary circuit.

WATERTIGHT (OSHA 29CFR1910.211 (d)) - Constructed so that moisture will not enter the enclosure.

WEATHERPROOF (OSHA 29CFR1910.211 (d)) - Constructed or protected so that exposure to the weather will not interfere with successful operation. Rainproff, raintight, or watertight equipment can fulfill the requirements for weatherproff where varying weather conditions other than wetness, such as snow, ice, dust, or temperature extremes, are not a factor.