Overload With Cl-Lst, Cl-Lmt And Cl-Let - ABB CL Series Applications Manual

Inside the logic relay
Monitoring of
short-circuit/
overload with CL-LST,
CL-LMT and CL-LET
I1-m1 6----ÄQ1
I1 6-------SM 1 6
I1-m16---ÄQ1
I16-----SM16
M1 6-------ÄQ4
I1-m16---ÄQ1
I16-----SM16
M1 6-------TT8
T8-------RM 1 6
M16------ÄQ4
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Depending on the CL type in use, it is possible to use the
internal inputs I15 and I16, R15, R16 to monitor for
short-circuits or overloads on an output.
• CL-LST:
I16 = Group fault alarm for outputs Q1 to Q4.
• CL-LMT:
– I16 = Group fault alarm for outputs Q1 to Q4.
– I15 = Group fault alarm for outputs Q5 to Q8.
• CL-LET:
– R16 = Group fault alarm for outputs S1 to S4.
– R15 = Group fault alarm for outputs S5 to S8.
Table 33: Status of error outputs
State of outputs
No fault found
At least one output has a fault
The following examples are for I16 = Q1 to Q4. I15 indicates
in the same way short-circuits and overloads on Q5 to Q8.
Example 1: Output with fault indication
The circuit diagram functions as follows:
If a transistor output reports a fault, M16 is set by I16. The
n/c contact of M16 switches off output Q1. M16 can be
cleared by resetting the CL power supply.
Example 2: Output of operating state
The circuit functions as described in example 1. An additional
feature is that when an overload is detected, the indicator
light at Q4 is actuated. If Q4 has an overload, it would 'pulse'.
Example 3: Automatic reset of error signal
The circuit diagram functions in the same way as example 2.
In addition the marker M16 is reset every 60 seconds by
timing relay T8 (on-delayed, 60 s). Should I16 remain at 1,
M16 will continue to be set. Q1 is set briefly to 1 until I16
switches off again.
1SVC 440 795 M0100
Status I15 or I16, R15 or R16
0 = switched off (n/o contact)
1 = switched on (n/o contact)