ABB CM Serie Instrucciones De Servicio Y De Montaje página 11

Operating principle
The current window monitoring relays CM-SFS.2 can be used for
the simultaneous monitoring of over- ">I" and undercurrents "<I"
in single-phase AC or DC systems. Depending on the configura-
tion, one c/o contact each i or both c/o contacts in parallel j
can be used for the over- and undercurrent monitoring.
The current to be monitored (measured value) is applied to termi-
nals B1/B2/B3-C. Open h or closed-circuit principle g as well
as an adjustable ON A or OFF B tripping delay are selectable.
ON-delayed A current window monitoring with parallel
switching c/o contacts j
If the measured value exceeds or drops below the adjusted
threshold value before the set start-up delay T
output relays do not change their state.
If the measured value exceeds or drops below the adjusted thresh-
old value when T is complete, the tripping delay T
S
A is configured. If T
is complete and the measured value is still
V
exceeding or below the threshold value minus / plus the fixed
hysteresis (5%), the output relays energize h /de-energize g.
If the measured value exceeds or drops below the threshold value
plus / minus the hysteresis and the latching function is not acti-
vated e, the output relays de-energize h / energize g. With
activated latching function f the output relays remain energized
h and de-energize only, when control supply voltage is inter-
rupted / the output relays remain de-energized g and energize
only, when control supply voltage is switched off and then again
switched on = Reset.
OFF-delayed B current window monitoring with parallel
switching c/o contacts j
If the measured value exceeds or drops below the adjusted
threshold value when the set start-up delay T
output relays energize h/ de-energize g, when B is confi-
gured, and remain in this position during the set tripping delay T
If the measured value exceeds or drops below the threshold value
plus / minus the fixed hysteresis (5%) and the latching function is
not activated e, the tripping delay T
, the output relays de-energize h / energize g, provided that
T
V
the latching function is not activated e. With activated latching
function f the output relays remain energized h and de-ener-
gize only, when control supply voltage is interrupted / the output
relays remain de-energized g and energize only, when control
supply voltage is switched off and then again switched on = Reset
When i is adjusted on the device, the functionality is equivalent
to the one described above. There is only to consider that in this
case, instead of both output relays, only one output relay each
will be switched.
">I" = 11 -12 /14 ; "<I" = 21
15 16 18
is complete, the
S
starts, when
V
is complete, the
S
starts. After completion of
V
-22 /24
25 26 28
Function diagrams
Current window monitoring, 1 x 2 c/o j
V
ON-delayed A without latching e
Current window monitoring, 1 x 2 c/o j
VI
OFF-delayed B without latching e
Current window monitoring, 1 x 2 c/o j
VII
ON-delayed A with latching f
Current window monitoring, 1 x 2 c/o j
VIII
OFF-delayed B with latching f
Current window monitoring, 2 x 1 c/o i
IX
ON-delayed A without latching e
Current window monitoring, 2 x 1 c/o i
X
OFF-delayed B without latching e
Current window monitoring, 2 x 1 c/o i
XI
ON-delayed A with latching f
Current window monitoring, 2 x 1 c/o i
XII
OFF-delayed B with latching f
Control supply voltage
Threshold value max.
Hysteresis
Measured value
Hysteresis
Threshold value min.
Open-circuit principle h
Output relay 1
Output relay 2
Green LED
Red LED
Yellow LED
Closed-circuit principle g
.
V
If the adjusted „threshold value max." minus the hysteresis is
< „treshold value min." plus the hysteresis, all LEDs flash syn-
chronously. The function of the output relays remains unchanged.
English
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