IMM 8001/8002 – Digital Motor Protection Relay
ICE / CEE
____________________________________________________________________________________________
IMU307-1 GB Ind. B
58
TESTS : Verification of ROTOR STALL protection AFTER START PERIOD [51STALL]
CONNECTION
Protection verification
Current injection
Coefficient
M
to be applied
Terminals
In =
1A
In =
5A
- single-phase
1.732
2-4 or 10-12
3-5 or 11-13
- balanced three-phase
1
2-4 phase 1
3-5 phase 1
10-12 phase 3
11-13 phase 3
Caution – the adjustment of coefficient K must be taken into account in the current to be injected :
K = In machine/IN
CT
Sequence of operations to be performed
Results to be obtained
Simulate normal operation of the motor with the instantaneous application of an
Ipos current equal to at least 1.5 In (start), then by reducing the
Ipos current to a value slightly below In (normal operation), or
wait for a time greater than
2 tst>
Or simulate motor operation by ap24V to the EL1 input (wire between
terminals A3 and B18), and wait for a time greater than
2 tst>
The rotor stalling after the start period is now permanently activated. It will
be inhibited when the current is cut off, or when EL1 is deactivated.
Check of overcurrent unit
Check of operating level Istl>
Put into service the protection, and route it to a chosen unit.
Note the value of operating level
Istl>
Note the value of time-delay
tIstl>
With the current generator connected according to the desired connection,
deduce
M
Gradually increase the current up to operating level
Istl>
taking
M
into
account.
If necessary, check the
Ipos
value on the display during the injection.
Check of time-delay tIstl>
Preset the current to at least 1.5 times programmed operating level
Istl>
Cut off the injection, then restore it (time-delay tIstl> starts after twice tst>)
Note : time 2 x tst> is increased by a time of about 0.2s. This additional
time is the time required for "motor start" information processing.
The Start Function indicator LED illuminates when the
displayed operating level is reached.
At the end of (2 x tst> +
0.2s
+ tIstl>) :
the selected relay must be energised,
the Internal Trip indicator LED must illuminate,
the fault message and related information must
be displayed.