15
Instruction Book
IB019008EN October 2016 www.eaton.com
FP-25-LV-VSR
Breaker-To-Motor Starter Conversion
5.3 ELECTRONIC OVERLOAD RELAY C440
The preferred overload relay provided on Eaton LV-VSR devices is the
electronic C440 relay. The relay offers four selections of trip classes:
1. The C440 overload device normally specified for the LV VSR
devices is the relay that provides two trip class selections,
10 or 20, plus a switchable ground fault trip system. The
ground fault trip threshold is 50% of the full load ampere
setting. See Figures 5.9 and 5.10.
Figure 5.9. C440 Overload Relay Faceplate and Functions
Figure 5.10. Ground Fault Unit
C440 NEMA Electronic Overload
1
LED (Unit Status)
3
Phase Imbalance Selection
2
FLA Dial
4
Operating Modes (Trip/Reset/Test)
LED
UNIT STATUS
1 flash / 2 seconds
Motor is running. Current < 1.15 Times the Dial Setting.
2 flash / 2 seconds
Motor is running. Current > 1.15 Times the Dial Setting.
No Flash
If the orange trip flag is visible, a trip has occurred.
No Flash
If the orange trip flag is not visible, motor is off or drawing < min FLA.
1
3
4
2
Figure 5.11. C440 Trip Current Adjustment and DIP Switches
Overload Tripping Current = 115%
Rotate FLA dial to current listed on motor nameplate for all motor
Service Factors.
Figure 5.12. Motor Service Factor Information for the C440
Overload Relay
2. A second rarely used C440 overload relay is available in
a 3-phase and single phase form. The 3-phase and single
phase configured device allows four trip class selections:
10, 20, 30, and 10A. Figure 5.11 shows the C440 with four
trip class selections.
3. Refer to Figure 5.10 or 5.11. C440 relay features include a
push/pull button for trip and test, a push button for reset,
and the full load current dial. Adjacent to the FLA dial, the
C440 electronic overload relay has ‘dip’ switch selections for
trip classes 10 or 20. (Most applications conforming to ANSI
guidelines use trip class 20.) The second position enables
or disables the built-in ground fault trip system. The third
position of the ‘dip’ switch enables or disables the phase
unbalance protection of the device. The fourth position of
the ‘dip’ switch enables or disables automatic reset of the
relay (see special warning about using automatic reset
feature). An indicating light on the face of the relay signals
when current is passing through the LV-VSR and when a
trip has occurred. Rapid blinking of the indicating light on
the C440 indicates that trip is imminent. Make the preferred
‘dip’ switch selections prior to energizing the LV VSR for the
first time.
4. A Full Load Current (FLA) dial is provided for selecting the
full load current setting, calculated based on the current
transformer ratio of the current transformers installed on
the LV VSR and the full load current determined from the
motor nameplate. When the C440 is set correctly, the relay
will provide tripping at 115% of the motor full load rating in
less than 10 seconds in accordance with UL 508. The C440
provided has markings 1 through 5 corresponding to the
5 ampere secondary current of the current transformers.
These markings designate trip thresholds that correspond
to the current passing through the windows of the current
transformers mounted on the rear of the LV VSR. Selections
are possible over the full range of the dial. The trip setting
must be made according to item 6 below prior to energizing
the LV VSR for the first time.
