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• In case of DOL starters
under no circumstances
should the relay be set
higher than the rated
current on the motor name
plate.
• In case of ASD starters
under no circumstances
should the relay be set
higher than phase current
i.e. 0.58 times the rated
current on the motor
nameplate.
• If the relay trips even when
set at the rated motor
current the suitability of
the starter / relay for the
particular application should
be checked with the nearest
Siemens office.
Operating Characteristics:
The given characteristics
(fig. 10) are average values of
all ranges and sizes of bimetal
relays and are mainly intended to
indicate the inverse time current
characteristics of the same. The
tripping times shown are for
relays starting from the cold
state. At operating temperatures
(heated at rated current) these
are reduced to about 25% of
the values obtained from the
characteristics.
Operation:
• For starting the motor, press
green push button, marked 'I'
(fig. 8).
• For stopping the motor, press
red push button, marked 'O'
(fig. 8).
• In case of hand reset type
overload relay, press blue
push button, marked 'R' (fig.
8) for resetting, after the relay
has tripped due to overload.
In this case you can restart
the motor only if you reset it.
• In case you want the starter
to be in 'Self Reset' mode,
the blue knob on relay (fig.
9) is to be pressed and
rotated in anticlockwise
direction; so that it comes
in position 'A', and its edge
Fig. 8 Starter front view
H - Hand Reset
A - Auto Reset
Fig. 9 Relay front view
flush with the relay surface.
In this mode even if the relay
trips on overload, it will be
automatically reset in max.
4 minutes. The motor can be
restarted only after the relay
is reset.
Fig. 10 Operating characteristics of 3US 5/6 relays
Maintenance:
'OFF'
button
• Keep the interior dust free.
• Re-tighten terminal screws
'ON'
from time to time.
button
• No maintenance is required
for overload relay and push
button. Do not open them.
'RESET'
button
• Blackening of silver coated
/ alloyed contacts does not
affect operational life. If
necessary, clean the contacts
of contactor with CRC 2-26.
Remove globules with
scrapper or screw driver with
minimum force. Under no
circumstances the contact
Blue
should be filed or dressed as
Reset
it will reduce the electrical life
Knob
drastically.
• If the contactor hums, clean
the magnet pole faces with
soft cloth.
• Replace contacts of the
contactor if they are
severely pitted or when
only 40% original contact
tip remains. For details of
contactor maintenance refer
to our 'Guide to Contactor
Installation & Maintenance'.
3 US 5/6
3 US 5/6
3
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