K2CU
K2CU
13
General
Refer to “External Connections” before using the K2CU with exter-
nal CTs.
When a temperature controller is used in combination with the
K2CU (except for the K2CU-F
jj
A-
j
GS), the heater element(s)
must be turned ON or OFF for 1 s or longer (although the heater ele-
ment(s) can be turned ON for 0.5 s according to the specifications).
The K2CU cannot be used with a phase-control circuit, inverter cir-
cuit, frequency-count circuit, cycle-control unit, or a motor load.
Mounting
Securely mount the K2CU as horizontally as possible although
there is no particular limitation of mounting directions.
Connection
Solderless-type terminal must be connected to the terminals se-
curely.
Wire the terminals correctly by referring to the external connections.
The terminals have no polarity. Be sure to connect 100 (or 110) V to
the 100-V (or 110-V) terminals and 200 (or 220) V to the 200-V (or
220-V) terminals of the K2CU-P or the K2CU-P may malfunction.
The control power source for the K2CU (except for the
K2CU-F
jj
A-
j
GS) must be supplied from the load side via a con-
tactor.
Be sure to impose a voltage between the 0-V terminal and 100-V (or
110-V) terminal or the 0-V terminal and 200-V (or 220-V) terminal of
the K2CU-P, otherwise the K2CU-P will not operate.
Operating Current Setting when Several Heaters are Used
The following table shows relative values of changes in the current
when any one of several heaters connected in parallel has burned
out. The current value under normal condition is 1. Use this table as
a guideline in determining the operating current.
Connection
n = 1
n = 2
n = 3
n = 4
n = 5
I
No. of heater = n
0
0.5
0.67
0.75
0.8
Current in burned-out phase
0
0.6
0.75
0.82
0.86
I
No. of heater
per phase = n
Current in other phases
0.87
0.92
0.95
0.96
0.97
Current in burned-out phase
0.58
0.77
0.84
0.88
0.91
I
No. of heater
per phase = n
Current in other phases
1
1
1
1
1
Note:
1. This table shows the respective change rates in current when any one of several heaters connected in parallel has burned out.
2. The current value under the normal condition is 1.
3. The values in this table are logical values. Actually, these values may vary slightly because of influence of unbalanced loads (heat-
ers). It is therefore recommended to test the actual current values and the load condition before determining the operating current,
especially when the current under the normal condition and that under an abnormal condition do not significantly differ.
