Watlow Series 142 Retrofit - Manual (Page 53)

Watlow Series 142 User’s Manual ■ 7
automatic power reset — A feature in latching limit
controllers that does not recognize power outage as a limit
condition. When power is restored, the output is re-ener-
gized automatically, as long as the temperature is within
limits.
electrical noise immunity — Ability of a temperature
control to operate normally in the presence of electrical
noise interference.
fixed set point — Temperature set point is preset at the
factory. It cannot be readjusted in the field.
latched output — Limit control output latches in de-
energized condition when overtemperature condition
occurs and cannot be reset unless temperature drops
below set point.
limit or limit controller — A highly reliable, discrete
safety device (redundant to the primary controller) that
monitors and limits the temperature of the process or a
point in the process. When temperature exceeds or falls
below the limit set point, the limit controller interrupts
power through the load circuit. A limit controller can pro-
tect equipment and people when it is correctly installed
with its own power supply, power lines, switch and sensor.
manual reset — A feature on a limit controller that
requires human intervention to return the limit to normal
operation after a limit condition has occurred.
safety limit — An automatic limit intended for use in
applications where an over-temperature fault may cause a
fire.
Glossary