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The DCR 50 is a simple off-line DC test to identify problems in the stator groundwall insulation system of large AC electric machines before an unexpected in-service failure occurs. Unlike the pass or fail of a DC or AC hi-pot test, the DC ramp test gives diagnostic information and can be stopped before a failure occurs.

Unlike a stepped voltage, the ramped voltage enables the user to separate the polarization and capacitive current components from the leakage current so that small insulation defects can be easily found.

A single-phase test usually takes less than an hour to perform and can be done by one person. The DCR 50 tests according to IEEE Std 95-2002.

The DC Ramp Test method has been proven in use (for almost 40 years) by the US Bureau of Reclamation and others on a wide variety of machines with asphalt, polyester and epoxy-mica insulations.

Test curves are captured on a PC to allow easy comparison to similar machines or past results.

DC Ramp Test Set


  • Automatically ramps voltage from 0 to 50kV

  • Ground presence detection and protection

  • Optional manual voltage control (0-50 kV)

  • Automatic trip protection (high/low tracking,  output limit, fault detection)

  • Built-in winding discharge circuit

  • Analog outputs for voltage and current

  • Connection to PC to: display results as test  progresses, store multiple curves and test  parameters for later analysis and display curves side-by-side for test comparison


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Ramped High Voltage DC Test for Winding Insulation

Model DCR 50

  • Simple, low risk, off-line test
  •  Identify onset of fault mechanisms
  • Diagnose damage and deterioration
  • Quick, accurate and repeatable results
  • Computer records for analysis
  • Tests to IEEE ® Std 95-2002 TM
Power Input 85-264 V AC, 2 A, 50/60 Hz
Output Voltage and Metering 0-50 kV DC, negative polarity
Ramp Rate 0-2.5 KV/min (continuously adjustable)
Output Current 1.0 mA max
Current Metering 0-1/2.5/5/10/25/50/100/250 uA
Pen Plotter Outputs 0-10 V DC fsd
PC PCMCIA A/D interface; Windows 2000 or XP
Operating Temperature o to +40 o C (+32 o to +104 o F); Storage: -25 o to +60 o C (-13 o to +140 o F) Humidity: 5-95% RH, non-condensing
Dimensions & Weight (2 cases) Control Unit: 20 x 37 x 48cm (8” x 15” x 19”), 10 kg (22 lb.)
  Above in case: 34 x 52 x 76cm (15” x 20” x 30”), 32 kg (70 lb.)
  HV Unit: 14.5 x 37 x 47cm (6” x 15” x 19”), 13 kg (29 lb.)
  Above in case: 34 x 52 x 76cm (15” x 20” x 30”), 34 kg (75 lb.)
Standards Tests to IEEE Std 95-2002 TM
  Œ Compliance
  EN61010-1 for safety
  EN61326 for EMC
  Bureau of Reclamation Report REC-ERC-78-7, “A Programmable DC High Voltage
  Ramped Test System for Electrical Insulation.”

*Specifications are subject to change without notice.

Model DCR 50

Kit Contents

  • Control Unit
  • HV Module
  • Control, HV and Grounding Cables
  • PCMCIA Interface Card & Cable
  • Notebook Computer with pre-installed Software
  • Operations Manual
  • Also available without PCMCIA and PC Other ADWEL Testing Products
  • EL CID, PDA Premium and COPA, STB-3, Couplers, Corona Probe and Wedge Tightness Detector