The All-Test's methods are static measurements that are performed on un-energized motors at low AC voltages - ensuring no stress is placed on the windings. In this respect, this equipment is useful for predictive maintenance (spotting faults early), as well as checking new, recently repaired or failed motors. The All-Test is also the only instrument of its type capable of displaying both inductance and impedance readings: inductance, phase angle, impedance and a current/frequency ratio.

Therefore, if you discover a phase unbalance in inductance, you can immediately compare it to impedance. This method can be used to determine if an unbalance is due to winding contamination or overheated windings, and can be evaluated at a glance on the unit or via the unit's respective software. Other inductive-based instruments required a 20-to-30 minute rotor test to determine the cause of a phase unbalance and can still leave the operator unclear as to the fault.

This particular piece of motor testing equipment comes into its own when utilising its ability to collect basic, de-energized electrical information which can be immediately reviewed by the operator. By using simple rules, the user can quickly evaluate the motor's condition, without having to understand the results, or how the motor itself works.

One of the instruments in the All-Test range is the All-Test Pro 31. This unit is effective in testing all types of motor, be it three-phase, single-phase or DC. Even traction motors and machine tool servos can be tested without removal or disassembly. In addition, small and large generators and transformers can be tested quickly and accurately.

Some of the faults we can detect with the All-Test Pro 31 include...

• Turn to turn and coil to coil faults
• Contaminated windings (such as grease, dirt and liquids)
• Phase unbalance and Z-unbalance (which result in a higher electrical bill and shorter motor life)
• Open windings and no conductivity
• Rotor faults such as broken bars, air-gaps and casting voids
• Insulation to ground faults

The instrument is as easy to use as any MegOhmMeter, has a rechargeable battery life of up to ten hours and weighs just 1lb - making it an extremely portable tool. The unit can also be supplied with Condition Calculator 4 - optional PC software that allows you to analyse your results and save them for future reference and comparison.

The All-Test Pro 31 gives you more information about motor electrical health than any other instrument in its class, enabling you to "make the call" on the spot. This makes the unit ideal for troubleshooting motor-related problems as well as pre-installation testing, and...

• Is effective in detecting inter-turn winding faults while troubleshooting drive trips
• Measures winding impedance to detect phase unbalances (manufacturing or rewind defects)
• Performs the industry's only sixty-second rotor test
• Test capacitors

Should you have any questions, or if you would like to discuss any of this further, then please do not hesitate to get in touch.