MPS

Shaft Voltage - Current Monitors

VCM-E vs VCM-C

Tracking the shaft voltage and current activity is essential on critical and/or large rotating machinery, such as utility turbine-generator units.

The Voltage-Current Monitor is available in two different models; the VCM-C and the VCM-E.  Below is a comparison of the two products.

Summary of the Two Models The VCM-E monitors continuous tracking of unit condition both locally and remote. The VCM-C is a basic unit with push button activated local monitoring.
Feature VCM-E VCM-C
Local Display Selectable for continuous display:
  • Peak Shaft Voltage *
  • Peak Shaft Current
  • Average Shaft Current
  • Power/Alarm Check
(Rotary switch selectable)		 Push button to display either:
  • Peak Shaft Voltage **
  • Peak Shaft Current
  • Average Shaft Current
  • Battery Voltage
(Rotary switch selectable)
Transmitter Remote signals, 4-20 mA, proportional to:
  1. Grounding Device Current (Peak and Average)
  2. Peak Shaft Voltage
 Not available
Alarms Remote Relay contact openings and Local LED’s for:
  1. Maximum Peak Shaft voltage
  2. Maximum Shaft grounding current
  3. Minimum Shaft grounding current
 Signals exceeding VCM range are indicated by the lighted overload LED, or display of 1_ _ _ when the push-to-read button is pressed.
Input Power Requirement 100-240 Vac
50/60Hz

9 Volts D.C.

 
Packaging Options NEMA 4 Enclosure (Model VCM-EN)
Explosion Proof (Model VCM-EE)		 NEMA 4 Enclosure (Model VCM-CN)
Explosion Proof (Model VCM-CE)
Number of Inputs Two
  1. An insulated shaft grounding device for the grounding current measurement.
  2. An insulated shaft voltage sensing device for the shaft voltage measurement. (Optional)
 One
  1. There is a single connection to the internal shunt from which either 1ohm grounded current or non grounded shaft voltage readings are made through an insulated shaft grounding device.
Explosion-Proof Installation The VCM-E is available for use in explosion proof or non-explosion proof environments.
* CENELEC EExd IIB+H2 T6 Class Approved units are available.		 The VCM-C is available for use in explosion proof or non-explosion proof environments.
* CENELEC EExd IIB+H2 T6 Class Approved units are available.
Mounting Requirements The current shunt should be mounted in close proximity to the grounding device. Transmitted 4-20 mA signals and alarm indications may be distributed to any location. A separate current shunt is not required. The VCM-C is installed in series with the grounding device .
Type of Brush Required Most types of insulated grounding device may be used. Most types of insulated grounding device may be used.

*For dual shaft contact device usage only.
**Push Button opens grounding device cable to ground.

SAFEGUARDING MACHINERY WORLDWIDE SINCE 1980.

800-647-7372