HT Instruments PV-ISOTEST Insulation Tester 100 MΩ (1010990)

Insulation faults and poor continuity are the hidden killers of photovoltaic installations, causing costly downtime and safety hazards. The HT Instruments PV-ISOTEST tackles this head-on by combining insulation resistance testing up to 2000 MΩ and low-resistance continuity checks in one rugged, IP65-rated tool. It is built for solar professionals who need fast, reliable verification of PV strings, inverters, and electrical panels in the field.

Who is it for

PV installers, maintenance technicians, and electrical inspectors who perform commissioning and periodic testing of photovoltaic systems. It is also suitable for general electrical contractors working on CAT III 1000V and CAT IV 600V installations.

Main features

• Insulation test voltages: 50V, 100V, 250V, 500V, 1000V DC
• Insulation resistance range: 0.001 MΩ to 2000 MΩ
• Continuity test with >200 mA current, range 0.00 Ω to 99.9 Ω
• TRMS AC/DC voltage measurement up to 600V AC and 1000V DC
• Automatic calculation of Polarization Index (PI) and Dielectric Absorption Ratio (DAR)
• Programmable test timer from 1s to 999s
• Backlit LCD display with IP65 protection
• USB interface for data transfer and memory for 999 measurements

Specifications

• Insulation test voltage: 50V, 100V, 250V, 500V, 1000V DC
• Insulation resistance range: 0.001 MΩ to 2000 MΩ
• Continuity test current: >200 mA
• Continuity resistance range: 0.00 Ω to 99.9 Ω
• DC voltage measurement: 0.0 V to 1000 V
• AC voltage measurement (TRMS): 0.0 V to 600 V
• Safety rating: CAT III 1000V, CAT IV 600V
• Display type: Backlit LCD
• Power supply: 6x 1.5V AA LR06 batteries
• Memory capacity: 999 measurements
• PC interface: USB
• IP protection class: IP65
• Operating temperature: 0°C to 40°C
• Standards compliance: IEC/EN 61010-1, IEC/EN 61557-2, IEC/EN 61557-4, IEC/EN 62446
• Polarization Index (PI) / Dielectric Absorption Ratio (DAR): Automatic calculation
• Test timer: Programmable (1s to 999s)
• Auto power off: Yes

Tips

For accurate insulation measurements on PV modules, ensure the array is disconnected from the inverter and that the test voltage is appropriate for the module's maximum system voltage. The IP65 rating allows use in dusty or wet environments, but avoid submerging the instrument. Use the USB interface to download stored measurements for reporting and analysis.