Overview

The D85R is a stand alone unit specifically designed to diagnose faults in very large electrical motors and windings, improving quality in the shop and reducing unnecessary and costly downtime. The 30kV output allows the user to thoroughly test large windings with lower impedance and higher capacitance. THe D85R satisfies the requirements of testing the windings of both AC motors and DC armatures by producing a surge with higher voltage and higher instantaneous current.

• Bar-to-Bar Vs. Span Testing: Manufacturers and rebuilders of industrial DC motors prefer the bar-to-bar test method over Span Testing to preserve quality control. When attempting to surge test lower impedance devices (ex. lift truck, transit, traction armatures, fields, interpoles), a tester may lack the necessary output current to achieve appropriate coil test voltage levels. The bar-to-bar method provides a higher energy insulation test than any other technique.
• The Baker Bar-to-Bar method overcomes span testing limitations by applying a specific controlled, lower voltage test, and measuring the surge voltage at the commutator bar-to-bar. The D85R provides a high instantaneous surge test current, and shifts the waveform ring frequency to a more observable rate. This method eliminates all of the significant drawbacks that equalizer windings can create during armature testing. Baker's bar-to-bar test method has detected faulty windings the span test and other methods missed. The Baker D85R offers the user the latest technology available to ensure the integrity of DC armature insulation.
• AC Motor Testing: The "Key element" of the surge test circuit is a grounded grid hydrogen thyratron tube. The tube conducts very high peak current. Such high instantaneous currents are needed to fully test the very low impedance windings of large motors or form wound coils. This current is only produced for a few microseconds by the discharge of a 0.1 microfarad capacitor. Voltage rise time is 100-200 nanoseconds (0.1-0.2 microseconds), so the D85R complies with IEEE Standard 522-1992 and IEC Standard 34-15 when testing motor windings and coils.
• The DC high potential test can also be done using the D85R. Test voltage is set by the output control from 500 volts up to 30,000 volts. current is displayed and an overcurrent trip circuit exceeds the trip level, the test is automatically halted. In its most sensitive setting, the protective circuit will operate as low as 10 microamps.
• The Resistance Test verifies the existence of dead shorts within the turn-to-turn coils, shows any imbalances between phases due to turn count differences, along with locating poor wire connections or contacts.
• The D85R is housed in a mobile case with the control unit permanently affixed to the upper face. These features along with the unsurpassed testing capabilities make the D85R powerful and technically advanced. The three phase selector switch is standard.

Specifications