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(8) When applying to a single-phase motor or DC motor
(8)-1
Standard type (trip class of 10A) and quick operating type (trip class of 5)
The standard type relays for all ratings and the
quick operating type relays for some ratings
include phase loss protection function as
standard.
Therefore, unless power is supplied to all the
phases, the relay may operate at a value
smaller than the set current value.
When applying to a single-phase motor circuit
or to a DC circuit, perform wiring according to
either one of the wiring patterns shown in
Figure 8.6 (a) and (b).
When using the wiring pattern (b), select an
appropriate heater rating so that the current
adjustment range of the thermal overload relay
is not exceeded.
(8)-2
Long-time operating thermal overload relays
Long-time operating thermal overload relays
are exclusively for AC applications.
When using the relay for a single-phase AC
motor, wire the circuit as shown in Figure 8.7
because each phase contains a reactor and
power must be supplied to each one of those
phases.
9. Maintenance and Inspection
9.1 Inspection before Operation
(1) Check if there are any loose screws.
(2) Check if there are any wire scraps, washers, etc. are caught in the product.
(3) Check if the thermal overload relay is set to the reset state because the relay may be tripped due to vibration or
shock during transportation.
9.2 Periodical Inspection
(1) Perform the initial inspection as early as possible after starting operation. Afterwards, perform the periodical
inspection.
(2) Periodically retighten terminal tightening screws.
(3) It is recommended that the product be renewed 10 years after the manufacturing date on condition that the
product has been used under the standard usage conditions as specified in the “Report on Recommended
Renewal Timing for Low Voltage Devices” issued by Japan Electrical Manufacturers' Association (JEMA).
(a) Connect wires so that power
is supplied in series to all
polarities.
(b) Set the adjustment dial to a
value approximately 10% higher.
Figure 8.6 When Applying to a
Single-phase Motor or DC Motor
Figure 8.7 Wiring for Long-time Operating
Thermal Overload Relays
Summary of Contents for TK13
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