OhmMeter

Blog · Updated 21 Jul 2026

AP-6688B 5000V Insulation Tester UK

Answer first: The AP-6688B 5000V insulation tester UK buyers shortlist is a digital megohmmeter aimed at higher-voltage motors and long cables when 1 kV tools run out of headroom.

Who it is for

Maintenance teams stepping up from hand-crank or 1 kV-only meters, rewind shops needing a second digital unit, and contractors mobilising project toolkits.

OhmMeter lists the AP-6688B with a 200 GΩ range at £106.16—confirm live voltage steps and accessories on the product page before ordering.

Voltage discipline

Always match test voltage to the asset rating. A 5 kV capability does not mean every motor should see 5 kV—follow your site procedure and manufacturer guidance.

Frequently asked questions

Is 5 kV always required?

Only when the asset and procedure call for it; keep lower steps for appropriate LV checks.

What does 200 GΩ give you?

Headroom to see high insulation values on dry, healthy equipment instead of pegging a low-range meter.

Calibration paperwork

Procurement should confirm whether a certificate is included or ordered separately.

Second unit logic

If the first meter is always booked out across bays, a matching second unit reduces waiting.

View product — £106.16