Installation Sheet: 2520T-INS
Effective: 07-15-84
123456789 Revision: 2-1-85
INSTRUCTIONS FOR INSTALLATION
& MAINTENANCE OF TEMPERATURE SWICHGAGES®
SERIES
20-1
20-St
25-1
A20-1
A25-1
ESR
TYPICAL TEMPERATURE SWICHGAGE®
A SWICHGAGE is an indicating mechanical gauge, having
adjustable limit contacts that act as switches when closed with
the gauge's pointer/contact. SWICHGAGES are available
various sizes and shapes to adapt to most applications, for
temperature, pressure, liquid level, vibration, or speed. The
are dry contact type switches for light duty electrical switch and
should be used with a Murphy Magnetic Switch or Transformer
Relay. Both electrical and mechanical experience necessary
for proper installation and care.
Temperature SWICHGAGE operate on the same mechanic
principal as pressure SWICHGAGESâ . Expansion of sending
fluid in the bulb, as temperature increases, translates into
pressure on the diaphragm, forcing the pointer to read
calibrated; closure with the limit contact initiates alarm and/or
shut-down.
TYPICAL TATTLETALE MAGNETIC SWITCH'"'
TATTLETALE Magnetic Switches
Murphy manufactures several, patented magnetic switches for
protection of the light duty SWICHGAGE contacts and to
ensure positive shut-down of equipment. There are magnetic
switches for Capacitor Discharge Ignition. Magneto, or battery
systems, and models for electric motor driven equipment.
TATTLETALES are pop-out indicators that show the cause of
shut-down. If several TATTLETALES are used in conjunction
with several different SWICHGAGE, the first one out will
lockout all other magnetic switches. Be sure the type of
Magnetic Switch matches the power source used to trip it.
· Note: At equipment start-up, the
magnetic switch reset button must be
held in until normal operation occurs,
unless closed SWICHGAGESâ are locked
out by time delay or lockout button. (Not
applicable for Mag. or C.D. power)
SEE BULLETIN M-6797 FOR MURPHY TATTLETALES & MAGNETIC SWITCHES
