Motor protection features – Magnetek 188-10130 User Manual
Page 33
RVS-DX, Digital Soft Starter Instruction Manual—4/01/04
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Motor Protection Features
The RVS-DX incorporates advanced microprocessor-based digital circuitry, which allows for
sophisticated motor protection with digital accuracy. The motor protection features are covered in
detail below.
Too Many Starts
The “too many starts” feature allows programming of the maximum allowable starts during the
“starting period”. The maximum amount of starts may be set from 1 to 10 starts within a 1 to 60
minute starting period.
Start Inhibit
The start inhibit sets the time period which starting is disabled after a “TOO MANY STARTS” trip.
The setting range is from 1 to 60 minutes.
NOTE:
When trying to start the motor before the “Start Inhibit” time has elapsed, the LCD will
display “WAIT BEFORE
⇒ RESTART: xx MIN.”.
Maximum Start Time (Stall Protection)
The maximum start time will trip the starter if the motor does not reach full speed during the
“Maximum Start Time”. The maximum start time is settable from 1 to 30 seconds.
Electronic Fuse (Shear-pin)
The electronic fuse is used to protect the starter and motor from high current. The electronic fuse has
two operating modes: one for during start, and one for during operation.
During starting: the starter trips when the current exceeds 850% of the motor FLA setting in 1
cycle or less.
During operation: (After acceleration period; “Run” LED will be on.) The starter trips when
current exceeds the set current level of 200 to 850% in the programmed delay time.
NOTE:
The electronic fuse is not intended to replace fast acting fuses to protect SCR’s.
Electronic Overload
The electronic overload becomes operational when the “RUN” LED is lit. The starter incorporates a
thermal memory register which calculates heating minus dissipation of the motor. When the thermal
memory fills up, the starter trips. The thermal register resets itself 15 minutes after the motor stops.
The electronic overload is settable from 75 to 150% of motor’s FLA. (Factory setting is 115%). The
tripping time at 5xFLA is adjustable from 1 to 10 seconds, thus allowing a trip curve selection.
Undercurrent
The undercurrent is operational when the motor is running. The starter trips when motor current
drops below the set undercurrent trip level for a time period longer than the undercurrent delay time.
The undercurrent setting ranges from (0=off) 20 to 90% of FLA, and the undercurrent delay ranges
from 1 to 40 seconds.