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Document NAE1038020
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10.2012
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© Bender Inc.
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Page 1/1
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Side 1/2
Bender Inc.
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USA: 800.356.4266 / 610.383.9200 / [email protected]
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Canada: 800.243.2438 / 905.602.9990 / [email protected]
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www.bender.org
VMD420
Installation Bulletin / Reference Guide
This document is intended as a reference guide for installing and using a BENDER VMD420 three-
phase voltage and frequency monitor. This document includes installation, setup, and usage instruc-
tions. For complete details, including installation, setup, settings, and troubleshooting, refer to the
VMD420 user manual, document number TGH1396en. This document is intended as a supplement
and not a replacement to the complete user manual.
Only qualified maintenance personnel shall operate or service this equipment. These instructions
should not be viewed as sufficient for those who are not otherwise qualified to operate or service this
equipment. This document is intended to provide accurate information only. No responsibility is as-
sumed by BENDER for any consequences arising from use of this document.
Installation
Mounting
VMD420 series devices may be DIN rail mounted, or screw mounted using the black clips lo-
cated on the top and bottom of the device. Screw mounting requires an extra black clip (article
number B98060008, sold separately).
! DANGER
• Disconnect all power before servicing.
• Observe all local, state, and national
codes, standards, and regulations.
HAZARD OF ELECTRIC SHOCK,
EXPLOSION, OR ARC FLASH
Wiring - General
Refer to figure 1 for wiring the VMD420. Use minimum
AWG 24, maximum AWG 12 size wire. Refer to VMD420
series user manual for complete technical details.
1. External supply voltage; 5A fuse
required for internal device pro-
tection
2. System connections (N connec-
tion is only necessary when N is
being used)
3. Alarm relay K1: SPDT contact
4. Alarm relay K2: SPDT contact
Figure 1 - VMD420 wiring diagram
Front Panel Display
1. LED “ON” (green): Illuminates when
power is applied to the device. Flashes
when the CT connection alarm is active.
2. LED “AL1” (yellow): Illuminates when
the prealarm is activated. Flashes when
the CT connection alarm is active.
3. LED “AL2” (yellow): Illuminates when
the main alarm is activated. Flashes
when the CT connection alarm is active.
4. Backlit LCD display
5. TEST / UP button: Activates self-test /
scrolls up inside main menu.
6. RESET / DOWN button: Resets device /
scrolls down inside main menu.
7. MENU / ENTER button: Activates main
menu / Confirms (momuntary push) or
goes back a step (held > 1.5 s) inside
main menu.
1
2
3
4
5
6
7
Figure 2 - VMD420 front display
1
2
3
4
Menu Flow Chart for Common Settings
Figure 4 through figure 8 on the reverse side of this document contain flow charts for modify-
ing commonly used features and settings in the VMD420’s main menu. Not all available fea-
tures are listed in this document. For more information, consult the VMD420 user manual.
R
T
Menu Legend
MENU / ENTER button
DOWN ARROW button
UP ARROW button
Momuntary button push
< 1.5 s
Hold button for at least 1.5 s,
then release
> 1.5 s
Wiring - Contacts
Using a normally closed or normally open contact utilizes two factors: wiring out of the proper
terminal, and setting the respective contact to normally energized or deenergized operation.
Refer to the chart below for relay conditions. For changing the energized state of the contact,
refer to “Figure 7 - Contact operation” on the reverse side of this document.
The factory default for the VMD420 is normally energized operation for relay K2, and normally
deenergized operation for relay K1.
Dimensions
Dimensions in inches (mm).
1.42” (36)
2.78”
(70.5)
1.87”
(47.5)
1.22” (31.1)
2.66” (67.5)
1.77” (45)
3.54” (90)
Normally energized mode (N/E)
Failsafe mode
“N/C” in device settings menu
Energized in the normal state
Relay will switch when the alarm is
activated, or when supply voltage
to the device is lost.
Power ON, normal state (no alarms)
Power OFF
Power ON, alarm state
11-12 OPEN
11-14 CLOSED
11-12 CLOSED
11-14 OPEN
11-12 CLOSED
11-14 OPEN
21-22 OPEN
21-24 CLOSED
21-22 CLOSED
21-24 OPEN
21-22 CLOSED
21-24 OPEN
Normally deenergized mode (N/D)
Non-failsafe mode
“N/O” in device settings menu
Energized in the alarm state
Relay will switch when the alarm is
activated.
Power ON, normal state (no alarms)
Power OFF
Power ON, alarm state
11-12 CLOSED
11-14 OPEN
11-12 CLOSED
11-14 OPEN
11-12 OPEN
11-14 CLOSED
21-22 CLOSED
21-24 OPEN
21-22 CLOSED
21-24 OPEN
21-22 OPEN
21-24 CLOSED
Relay Operation Setting
Device Alarm State
K1 STATE
K2 STATE
Device Relay Conditions
