© 2016 Littelfuse Protection Relays & Controls
Protection Relays
Voltage Monitoring Relays
www.littelfuse.com/
Rev: 1-A-062716
www.littelfuse.com/wvm
WVM SERIES
Read Memory: Fault(s) stored in the memory are indicated
when the yellow LED is flashing, up to 10 faults are noted.
Memory Reset: To clear the memory of all faults
stored, rotate selector to Clear Memory for 5 seconds.
The yellow LED will turn off.
Memory Overload: Only the 10 most recent faults
are retained.
Random Start Delay: A new 3 to 15s random start delay is
selected by the microcontroller when a fault is corrected and
when the operating voltage (L1, L2, L3) is applied to the WVM.
A random start delay does not occur when the reset is manual.
Automatic Restart: Upon fault correction, the output will
re-energize after a random start delay.
Automatic Restart Upon Fault Trip: When a fault is sensed for
the full trip delay, the output de- energizes and a restart delay
is initiated. This delay locks out the output for the delay period.
Should the fault be corrected by the end of the restart delay, the
output will re-energize after a random start delay. A restart delay
will also occur when operating voltage (L1, L2, L3) is applied to
the WVM.
Manual Reset: After a fault condition is corrected, the WVM can
be manually reset. There are two methods; a customer supplied
remote switch, or the onboard selector switch.
Manual Reset (Onboard): Rotate selector switch from the
Manual Reset position to Auto Restart w/ Delay then back
again to Manual Reset within 3 seconds. The output will
immediately energize.
Remote Reset: Reset (Restart) is accomplished by a momentary
contact closure across terminals 1 & 2. The output will
immediately energize. Remote switch requirements are ≥10mA
@ 20VDC and the reset terminals are not isolated from line
voltage. A resistance of ≤20KΩ across terminals 1 & 2 will cause
immediate automatic restart.
Automatic Restart Upon Fault Correction: (P/N includes an R)
When a fault is sensed for the full trip delay, the output relay
de-energizes. Upon correction of the fault, a restart delay
begins. At the end of this delay, the output will re-energize after
a random start delay. If a fault occurs during restart timing, the
restart time delay will be reset to zero, and the output will not
energize until the restart delay is completed.
Accessories
LPSM003ZXID (Indicating),
LPSM003Z (Non-indicating) Fuse Holders
Littelfuse POWR-SAFE Dead Front holders
provide optimum protection to personnel for
Class CC and Midget-Style fuses. 600 VAC/DC
0KLK002.T Midget Fuse (2 Amp)
10 x 38 fast acting, high-interrupting capacity,
current-limiting type fuse. 600 Vac/500 Vdc
C103PM (AL) DIN Rail
35 mm aluminum DIN rail available in a 36 in.
(91.4 cm) length.
Specifications
Line Voltage
Type 3-phase delta or wye with no connection
to neutral
Operating Voltage Model Adj. Line Voltage Range
240 200-240VAC
380 355-425VAC
480 400-480VAC
600 500-600VAC
AC Line Frequency 50/60 Hz
Overvoltage, Undervoltage,
& Voltage Unbalance
Overvoltage Trip Point 109-113% of adjusted voltage
Reset Voltage -2% of trip point
Undervoltage Trip Point 88-92% of adjusted voltage
Reset Voltage +2% of trip point
Voltage Unbalance Adjustable from 2-10%*
Trip Delay Adjustable from 0.25 - 30s ±15%
Phase Loss ≥ 15% unbalance
Response Time ≤ 200 ms
Random Start Delay Range 3 - 15s
Reset (Restart) Delay
Low Range 0.25-64s ±15%
Normal Range 6-300s ±15%
High Range 0.25-64m ±15%
Fault Memory
Type Nonvolatile RAM
Capacity Stores last 10 faults
Status Indicators 6 LEDs provide existing status &
memory readout
Note: 50% of operating line voltage must
be applied to L1 & L2 for operation of
status indicators
Output
Type Electromechanical relay
Form Isolated, SPDT
Rating 10A resistive @ 250VAC; 6A inductive
(0.4 PF) @ 250VAC
Life Mechanical - 1 x 10
7
Protection
Phase Reversal/Failure ASME A17.1 Rule 210.6
Motors and Generators NEMA MG1 14:30, 14:35
Surge IEEE 62.41-1991 Level B
Isolation Voltage ≥ 2500V RMS input to output
Mechanical
Mounting Surface with 2 or 4 #8 (M4 x 0.7) screws
Dimensions H 175.3 mm (6.9”); W 111.8 mm (4.4”);
D 61.0 mm (2.4”)
Termination Screw terminals with captive wire clamps for
up to #12 AWG ( 3.2 mm
2
) wire
Environmental
Operating/Storage
Temperature -40° to 65°C / -40° to 85°C
Weight ≅ 25 oz ( 709 g)
* Unbalance reset is 90% of the unbalance setting (i.e. VUB at 5% reset is 4.5%)
