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The following adjustments to the Solid State Overload
Relay are illustrated ir1 Figure 2. The adjustments should
be performed in the following order.
The settings as the unit is received from the factory are
as follows:
• Full-load current at minimum.
• Protection class at 20.
This setting is the current beyond which the Solid State
Overload Relay will trip. Use the following guidelines to
determine the appropriate setting:
• For motors with a service factor of 1.0, set the full
load current on the Solid State Overload Relay to
0.9 times the full-load amps (FIA) rating on the
motor's nameplate.
• For motors with a service factor of 1.15-1.25, set the
full-load current on the Solid State Overload Relay
to the FIA rating on the motor's nameplate.
Press on the tamper-resistant cover above the FIA dial,
then lift up near the tab on the other side to remove the
cover. Rotate the FIA dial so that the arrow on the dial
points to the desired current, as indicated by the
ampere markings around the dial. Do not rotate past the
marked area. The knob moves in small steps to allow
precise adjustment of the full-load current. Replace the
tamper-resistant cover to provide additional
protection. To protect against unauthorized persons'
tampering with the settings, insert a wire lock through
the locking tabs.
The Solid State Overload Relay contains a trip function
activated by a phase loss. This protection is activated when
one phase loses current and either one of the remaining
phase currents exceeds 95% of the minimum FLA of the
Overload Relay. A phase loss trip occurs within 3-6 seconds
of loss of phase current.
Tamper-R esi stant Full-Load Current
Cover
Protecti ? n Class
S itch
Open Collector
Figure 2. Top face of Solid State Overload Relay, with controls and
features indicated.
Adjusting the Solid State Overload
Relay
Full-Load Current Adjustment
Phase Loss Sensitivity
dust
Adjustment Dial
Power Factor Correction
Capacitor Terminals
Remote Reset
Pocket
0
CAUTION: The slide switch must be in one of the three
ATTENTION: Le bouton de selection de la classe de
detent positions. If the slide is between one of the
detents, the default is protection class 30.
protection doit etre dans une des trois positions stables.
Si le bouton se trouve entre deux positions, la classe de
protection est fixee a 30 par default.
Set the desired protection class to 10, 20, or 30 by
sliding the switch to the appropriate detent position.
The time-current curves for the protection classes are
shown in Figure 3. Select the class appropriate to the
particular application.
The following procedure can be performed periodically
to insure that the Solid State Overload Relay contacts
have not welded because of a short circuit in the control
circuit.
1. Disconnect all power and control wiring from the
Solid State Overload Relay.
2. Place a bell set or resistance-measuring instrument
across the NC relay terminals (95 and 96).
3. Depress and release the reset button to insure that
the Solid State Overload Relay is reset. In this
condition, there should be continuity between the
terminals.
4. Slide the mechanical trip test lever from right to
left to trip the Solid State Overload Relay. There
should be no continuity, indicating that the
contacts are operating normally.
5. If the contacts work properly, reconnect power
and control wiring and reset the Solid State
Overload Relay for normal operation.
indicated with the relay
defective and must be replaced.
Protection Class Setting
1000
i
.'\.
I
� ! �
- -
j 100
-
--
....
--..
......
........
E
....
�
j::
: t
1:1)
C
10
i
I
1
2
Multiples of Full Load Amps setting
Figure 3. Time-current curves (cold state) for the protection classes.
Test
for Welded Contacts
continuity is
tripped,
the relay
I
'
I
-
--
:
-......L
�
-r--,...._
-.......
r-
�
Class 30
-!--,....
....___!
i-,. r-,...
Class 20
FF
Class 10
I
i
I
!
3
4
5
6
7
8
9 10
If
is
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