Description
Overtemperature protection using a thermal image of the protected unit.
B. Features
selectable thermal image for:
1st. order model
universal thermal image defined by the impulse response
of the thermal system (see Fig. 3.5.19.1)
alarm and tripping stages
adjustable initial temperature rise
extended thermal time constant when stationary
takes account of temperature coefficient of resistance
insensitive to d.c. components
insensitive to harmonics
single or three-phase measurement
highest phase value detection in the multi-phase mode
independent scaling of the impulse response for the universal
thermal image (entry of a table)
40 temperature rise calculations per thermal time constant
(for 1st. order model) or 200 calculations per duration of the
impulse response.
C. Inputs and outputs
I. C.t./v.t. inputs:
current
II. Binary inputs:
blocking
standstill
III. Binary outputs:
alarm
tripping
IV. Measurements:
temperature rise
power dissipation
current.