VC
CAUTIONS FOR USE
General Usage Conditions
• Ambient temperature (relative
humidity):
–10C°–40C° (45%–85% RH)
40C°–55C° (45%–75% RH)
(No condensation or freezing)
• Elevation: 2,000 m or less
• Operating circuit voltage fluctuation
range:
80%–110% of rated voltage (cold state)
• Rated frequency: 50/60 Hz
Notes on relay selection
• Select a relay such that the load
capacity is within the rating of the
solenoid switch.
• At the maximum rated motor capacity,
the product has an electrical switching
durability (service life) of 250,000
operations or more. This is suitable for
consumer and light industrial
applications.
• In certain usage environments
(temperature, humidity, oil mist, etc.),
the service life of the contacts may be
shortened. For applications such as
industrial machinery where the usage
environment is poor, select a model that
provides some performance margin.
Contact your National dealer for
assistance when making a selection.
• These relays are not suitable for
applications such as inching or
plugging.
• Using the wrong coil voltage can cause
the coil to burn out. Particular care
should be taken when selecting the coil
voltage in cases where the main circuit
and operating circuit have different
voltages.
• When choosing a thermal relay, make
sure the current adjustment range is
appropriate for the full load current of
the motor, regardless of the voltage of
the main circuit. Operation cannot be
guaranteed if the motor is outside the
current adjustment range.
• The relays are sealed type units and are
adjusted at the factory. They are not
intended to be disassembled by the
user. It is not possible to replace
individual contacts or coils.
• The minimum usable current is the
approximate lower limit value at which
switching operation is possible at very
small load levels. The actual minimum
usable current may differ depending on
factors such as the usage environment.
Relays should therefore be tested at the
actual load level before use.
Installation notes
Mounting
• Mechanical shocks from being dropped,
etc., can cause malfunctions. Handle
relays with care.
ds_24401_0018_en_vc: 110607D
• Avoid using relays in extreme
environments, such as locations subject
to excessive heat, humidity, dust,
corrosive gases, vibrations, mechanical
shocks, or direct sunlight.
• Avoid using relays in locations where
they could be exposed to rain or water
spray. (Such conditions could cause
malfunctions.)
• As shown in Figure 1, secure the ends
of the mounting plate to the mounting
bracket using 4 mm screws, then snap
the relay into place. To remove the
relay, carefully pry loose the hook of the
mounting bracket with the tip of a
screwdriver, as shown in Figure 2, and
then pull the relay out. (Do not to apply
too much force with the screwdriver to
avoid bending the mounting bracket.)
Figure 1 Mounting bracket
Figure 6
6.35
0.8
VC15(4P) should not be used with a
receptacle tab because the insulation
distance cannot be guaranteed.
3) Insert the receptacle firmly to prevent it
from loosening. Removal requires a
pulling force of 2 to 4 kg, so avoid trying
to remove two at the same time. Make
sure to remove only one at a time.
4) Avoid applying solder to terminals.
Figure 5
Straight type
Model
VC15
VC20
VC15 4P
VC20 4P
Flag type
Receptacle tab
combined type
AMP 250 series receptacle
Straight type, flag type,
receptacle tab combined type
Straight type, flag type,
receptacle tab combined type
Straight type, flag type
Straight type, flag type,
receptacle tab combined type
Mounting holes
Figure 2
8
• When relays are mounted side-by-side
horizontally, the operation indicators are
located on the side. Therefore, they
should be positioned at least 5 mm
apart, as shown in Figure 3. In addition,
when they are mounted side-by-side
vertically, as shown in Figure 4, make
sure to leave sufficient space in
between them to allow insertion of a
screwdriver to remove the mounting
brackets.
Figure 3
7.5
5
Figure 4
10
Wiring connections
• Connections to screw terminals
Terminal
dimensions
4.5
Terminal
screw
Up terminal
Max. conne- Suitable crimp-
ction wire
type terminal
Standard tighten-
ing torque
7.4
φ
1.6
2 mm
2
M3.5
2-3.5
2Y-3.5
0.8-1.2N • m
8.2-12.2kgf • cm
Full-up terminal
5.1
8.6
10
φ
2
3.5mm
2
M4
3.5-4
1.2-1.8N • m
12.2-18.3kgf • cm
• Plug-in terminal connections
1) When removing a VC relay from the
socket, pull it straight out. Pulling the
relay out at an angle could bend the
plug-in terminals.
2) The receptacles listed in the table
below may be used with relays having
plug-in terminals. However, the
Usage precautions
• If there is concern that contact problems
(fusing, open-phase, etc.) or the auto-
reset operation of thermal relays could
cause secondary damage, appropriate
safeguards should be built into the
system.
• Make sure not to confuse the terminal
positions when using relays. The
terminals are marked on the nameplate.
Be particularly careful regarding the
positions of terminal b and the coil
terminal.
• Circuits through which current is flowing
continuously for long periods due to the
operation of the relay, etc., should be
designed so that they are in a non-
excited state when left idle. (Examples
include circuits for emergency lamps,
warning devices, and fault detectors
that reset only in case of emergency
and use terminal b to issue warnings.)
Maintenance and inspection
• Due to the danger of electric shock,
always shut off power when performing
maintenance or inspections.
• Periodically retighten terminal screws to
prevent the possibility of overheating or
fire due to loosening.
• If there is concern that contact problems
(fusing, open-phase, etc.) could cause
secondary damage, perform checks
regularly and replace relays as soon as
any problems are discovered.
• If a thermal relay is tripped, correct the
problem and then lightly press the reset
button to restart operation.
5
7
3.4