Fluke 1587 Insulation Tester, 50 V Min, 1000 V Max CAT IV, CAT III

This insulation tester is a handheld digital instrument designed to combine insulation resistance testing with multimeter functions for maintenance and fault-finding in industrial and commercial electrical systems. It operates from AA batteries and is suitable for field use, offering insulation test voltages from low-voltage checks up to high-voltage diagnostics while providing protection against live circuits before initiation.

• Insulation test range to 2GΩ for high-resistance detection
• Test voltages from 50V to 1000V for versatile diagnostics
• 1mA nominal test current to limit stress on components
• CAT IV 600V and CAT III 1000V safety rating for site use
• Digital display with 6000-count backlight for clear readings
• Battery life approximately 1000 h enabling extended field use

• Suitable for preventative maintenance on motor windings and drives
• Ideal for insulation resistance checks on switchgear and panels
• Used for troubleshooting contaminated or moist insulation
• Suitable for commissioning tests on transformers and cables
• Can be used with VFD-driven equipment using low-pass filtering

The unit detects Terminal voltage above 30V and inhibits insulation tests to prevent inadvertent live testing.

It auto-discharges capacitive voltage and is operable with capacitive loads up to 1 μF.

The instrument functions between −20 °C and 55 °C and is specified for non‑condensing humidity up to 95% at 10 °C–30 °C with reduced limits at higher temperatures.

It meets CE and CSA approvals and conforms to IEC safety categories for measurement environments.

The supply includes a remote probe, test leads and crocodile clips Plus a hard carrying case and a K‑type thermocouple where fitted.