The LT300 high current loop tester offers simple, fast, two-wire operation for high current loop testing across a wide range of frequencies and supply voltages. It has a large, clear display that aids visibility in poor conditions. Two models are available: LT300-EN-00 - with red/green leads LT300-EN-BS - with BS1363 mains plug lead The high current loop test provides fast, accurate and stable results with a resolution to 0.01 Ω on the 20 Ω range. Frequency range Supply frequency is indicated upon connection to the supply. This will automatically set to the measured supply frequency either 16 Hz, 50/60 Hz or 400 Hz. Testing will commence automatically. Loop Impedance measurement: Two loop impedance ranges are provided. 20 Ω - Resolution to 0.01 Ω 200 Ω - Resolution to 0.1 Ω Supply voltage: Operational supply range extends from 50 V to 550 V (400 V @ 16 Hz), with a warning for voltages over 330 V high- lighting accidental phase to phase connections on a nominal 230 V system. Single Phase CATIV 300 V phase to earth, as well as 550 V phase to phase applications (400 V @ 16 Hz) GENERAL The instrument is housed in a rubber armoured case with a built-in cover to protect the display when not in use. The IP54 weatherproof rating provides excellent protection in adverse conditions. The instrument is supplied with either a two wire (red/green) lead set, or a mains plug test lead for access to wall sockets, a certificate of test and a hard carry case.
The LT300 is a high‑current loop tester designed for single‑ and three‑phase testing with a frequency range of 16 Hz to 400 Hz and a CAT IV 300 V rating. It features a large clear display, a rubber‑armoured case with a built‑in cover, and an IP54 weatherproof rating for use in harsh environments.
The instrument is supplied with either a red/green two‑wire lead set or a BS1363 mains plug lead, along with a hard‑carry case. Power is provided by eight AA cells (alkaline or NiMH). The manual includes detailed specifications, operating procedures, and safety compliance information (EN 61557).
| Voltage measurement range | 0 V to 550 V (400 V @ 16 Hz) |
|---|---|
| Operating frequencies | 16 Hz, 50/60 Hz, 400 Hz |
| Operating temperature | -10 °C to +60 °C |
| Storage temperature | -25 °C to +70 °C |
| Maximum humidity | 90 % RH @ +40 °C |
| Maximum altitude | 2000 m |
| Battery | 8 × AA (LR6) alkaline or NiMH rechargeable cells |
| Weight | 980 g |
| Dimensions | 203 × 148 × 78 mm |
The LT300 measures voltages from 0 V up to 550 V (400 V at 16 Hz).
It operates at 16 Hz, 50/60 Hz, and 400 Hz.
The instrument is powered by eight AA (LR6) alkaline or NiMH rechargeable cells.
The LT300 has an IP54 weatherproof rating.