K2CM-Q2MA Datasheet, PDF (9/16 Pages) Omron Electronics LLC – Solid-state Relay Enables Choice of Three Operating Functions (Overcurrent, Openphase, and Reverse-phase)

LED Indicators
When the motor circuit trips due to overcurrent, open-phase, or
reverse-phase, the respective LED indicator lights (continuously).
The overcurrent indicator also indicates the start of operation.
Overcurrent operating value
(115% of current-setting value)
Motor current
Bright
Bright
Dimmed
Start
Trip
• With the inverse-type models, when the motor current exceeds the
overcurrent operating value, the overcurrent indicator blinks at the
bright level and then remains lit at the dimmed level. After the oper-
ating time has elapsed, with the manual resetting models, the
motor circuit trips and the overcurrent indicator remains lit at the
bright level, whereas with automatic resetting models, the indicator
remains lit at the bright level until the motor current descends below
the resetting value.
• Since the indicator status is not stored in memory when the opera-
tion power supply is turned OFF, be sure to check which indicators
were illuminated when the motor circuit was tripped.
The functions of the K2CM can be used in the following seven combi-
nations. For each function, turn ON the corresponding setting switch.
Function Overcurrent
Combination
1
ON
2
3
4
ON
5
6
ON
7
ON
Open-phase
ON
ON
ON
ON
Reverse-phase
ON
ON
ON
ON
When the setting switches for overcurrent, open-phase, or reverse-
phase function are turned OFF, the following functions becomes
invalid.
Function setting switch
set to OFF
Overcurrent
Open-phase
Reverse-phase
Invalid function
Time setting and multiplication
“High” and “Low” imbalance factors
“Forward” and “Reverse” function
1. Overcurrent Setting Switches
These switches select the overcurrent setting and the multiplying fac-
tor linked with operating time setting.
Overcurrent
ON Enabled
detecting function _{OFF Disabled}
Time setting
× 4 (s) Time setting scale value × 4 = 8 to 40 s
multiplying factor _{× 1 (s) Time setting scale value × 1 = 2 to 10 s}
2. Open-phase Setting Switches
These switches select the open-phase detecting function and the
“High” or “Low” current imbalance factor for operation.
Open-phase
detecting
function
Imbalance factor
ON
OFF
High
Low
Enabled
Disabled
The motor circuit operates at an
operating imbalance factor of 35
±10%.
The motor circuit operates at an
operating imbalance factor of 60%.
3. Reverse-phase Setting Switches
These switches select the reverse-phase detection function and
reverse-phase polarity. By selecting the reverse-phase polarity
accordingly, the K2CM can operate normally without changing the
connections when wired with the order of the phases reversed.
K2CM
Reverse-phase
detecting
function
Reverse-phase
polarity
ON
OFF
Enabled
Disabled
Normal
Reverse
The motor circuit trips at reverse-
phase when a reverse-phase is
detected.
Used when a reverse-phase
connection is made in the power line
of the motor at a point before the
current transformer (including
external current transformer).
If the K2CM detects reverse-phase although the motor is rotating in
the forward direction (e.g., because of incorrect wiring of power
lines), set the reverse-phase polarity switch to the “Reverse” position
to enable normal operation.
Phase condition Normal
Connections
R ST
R ST
Motor
relay
M
Reverse
R ST
(A)
R ST
Motor
relay
(B)
M
Reverse
R ST
(C)
R ST
Motor
relay
(D)
M
Reverse-phase
polarity switch
position
Trip
Direction of
motor rotation
Normal
None
Forward
Normal
Normal
Yes
Reverse
(See below.)
None
Reverse
Coun-
ter-
mea-
sure
Reverse-
phase
polarity
switch
position
Wiring
Reverse Reverse Reverse Reverse
Wiring Wiring Wiring Wiring
changed changed changed changed
at (A). at (B). at (C). at (D).
Direction of
Forward
motor rotation
Note: The K2CM detects reverse-phase at a point before the current
transformer. If a reverse connection is made at the load side far
from the current transformer and the motor rotates in the re-
verse direction, the K2CM does not detect the reverse-phase.
Reverse-detectable Range
R ST
Detectable:
R ST
Reverse-phase state can be detected with the
motor protective relay only on the power supply
side.
M
Undetectable: Reverse-phase state on the motor side cannot
be detected with the motor protective relay.
* The reverse-phase polarity switching function is applicable to cur-
rent reverse-phase detection models only.
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