
UNI-T UT505A Insulation Resistance Tester & Multimeter
Overview
The UT505A puts a CAT IV 600 V insulation tester and a True-RMS digital multimeter in one handheld. It tests insulation resistance up to 20 GΩ at voltages from 50 V to 1000 V to IEC 61557, then switches to a 6000-count multimeter for AC/DC voltage, resistance, capacitance, frequency, and low-resistance measurement — so the tool that confirms a winding is open is the same one that checks its insulation.
Insulation work includes Polarization Index and DAR diagnostics, stepped-voltage testing, and automatic discharge, with 99 result groups stored on-board. It's backed by UNI-T's nearly 40 years of test-meter manufacturing.
Key Features
- Insulation resistance up to 20 GΩ, accuracy ±(1.5%+5)
- Test voltages: 50 V, 100 V, 250 V, 500 V, 1000 V (IEC 61557)
- True-RMS 6000-count digital multimeter built in
- AC/DC voltage to 600 V; capacitance, frequency, low and general resistance
- PI and DAR insulation diagnostics
- Stepped-voltage testing and automatic discharge
- 99-group data storage
- CAT IV 600 V safety rating
UT505A Details
Two Instruments in One
The UT505A combines a 1000 V insulation tester with a full True-RMS multimeter, so a single handheld covers both the insulation check and the routine electrical measurements around it — voltage, resistance, capacitance, frequency, and continuity-class low resistance.
Insulation Testing to 20 GΩ
Five test voltages from 50 V to 1000 V, a 20 GΩ measurement range, and IEC 61557 compliance cover insulation checks on motor windings, cables, and switchgear at low and medium voltage.
PI, DAR & Stepped Voltage
Timed PI and DAR diagnostics reveal moisture and contamination, while stepped-voltage testing stresses the dielectric in stages to surface marginal insulation a single reading would pass.
True-RMS Multimeter
A 6000-count True-RMS meter reads AC and DC accurately on distorted waveforms common around drives and non-linear loads, with the resistance, capacitance, and frequency functions a maintenance tech reaches for daily.
Safety & Field Build
Automatic discharge clears stored charge after each insulation test, and the CAT IV 600 V rating suits work on distribution systems. Storage holds 99 result groups for later review.
Compare the UT505 Series
| UT505A | UT505B | |
|---|---|---|
| Max insulation resistance | 20 GΩ | 200 GΩ |
| Auto fuse check | — | Yes |
Applications
Combined insulation and electrical checks on motor windings, cables, and switchgear; preventive maintenance where one tool needs to do both jobs; and field troubleshooting that moves between insulation testing and routine multimeter measurements.
Frequently Asked Questions
What does the UT505A measure besides insulation resistance?
It is a full True-RMS 6000-count multimeter — AC/DC voltage, resistance, capacitance, frequency, and low resistance — in addition to insulation testing to 20 GΩ.
What test voltages does it provide?
50 V, 100 V, 250 V, 500 V, and 1000 V, to IEC 61557.
How is the UT505A different from the UT505B?
The UT505A reads insulation to 20 GΩ; the UT505B extends the range to 200 GΩ and adds an automatic fuse check.
Warranty
This product includes a standard 1-year warranty covering manufacturing defects and component failures under normal use conditions.
UNI-T stands behind every product we sell. If you experience any issues within the warranty period, our US-based support team is here to help with troubleshooting, repair, or replacement.
| Max Test Voltage | 1000V |
|---|---|
| Max Resistance | 2GΩ |
| Short Circuit Current | <2mA |
| AC Voltage | 600V, ±(2%+3) @ 0V~600V |
| DC Voltage | 600V, ±(2%+3) @ 0V~600V |
| CAT Rating | CAT IV 600V |
| Instrument Type | Insulation Tester |
Features
- Polarization Index
- Auto Discharge
- Comparison Function
- Auto Ranging
- High Voltage Alarm
- Auto Power Off
- Audible Visual Alarm
- Time Setting Function
- Data Hold
- Analog Bar Graph
- Backlight
- Low Battery Indication
- True RMS
- Comparison Measurement
- PI / DAR
Full specifications (17)
| Details | |||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Insulation Resistance |
|
||||||||||||||||||||||||||
| Resistance Accuracy | ±(1.5%+5) | ||||||||||||||||||||||||||
| Step Voltage | 10% steps at 50%~120% of range | ||||||||||||||||||||||||||
| Data Storage | 99 | ||||||||||||||||||||||||||
| Test Voltage Accuracy | 0% – 20% | ||||||||||||||||||||||||||
| Charge Current | 2mA | ||||||||||||||||||||||||||
| Capacitance | 500μF | ||||||||||||||||||||||||||
| Features | |||||||||||||||||||||||||||
| Frequency | 1kHz | ||||||||||||||||||||||||||
| Count | 6000 | ||||||||||||||||||||||||||
| DAR | 60s/15s and 60s/30s | ||||||||||||||||||||||||||
| General Resistance | 0.01 kΩ to 10 MΩ, ±(3% + 3) | ||||||||||||||||||||||||||
| Low Resistance | ±(1.5%+3) | ||||||||||||||||||||||||||
| General Information | |||||||||||||||||||||||||||
| Battery | 1.5V AA × 6 | ||||||||||||||||||||||||||
| Dimensions (W×H×D) | 103 × 225 × 59 mm | ||||||||||||||||||||||||||
| Weight | 630 g | ||||||||||||||||||||||||||
| Warranty | 1 year | ||||||||||||||||||||||||||
| Certifications | CE|cETLus | ||||||||||||||||||||||||||
Data Sheets and Manuals
- Not currently available. Contact us with questions.