Loop & RCD Testers

A loop tester measures earth fault loop impedance to confirm that sufficient fault current will flow to operate a fuse or circuit breaker within a safe disconnection time. A Residual Current Device (RCD) tester verifies that a residual current device trips correctly when a fault is detected, protecting against electric shock and fire risk. Together, these instruments are essential for electricians, facilities managers, and safety inspectors verifying the safety, compliance, and performance of electrical circuits and protective devices.

RS Hong Kong stocks a comprehensive range of loop and RCD testers in digital formats, including standalone earth fault loop tester models and combined loop impedance and RCD units. The range covers maximum voltage measurements from 230V up to 1,000V, ensuring you’ll find the one that fits your needs.

Types of Loop & RCD Testers

Loop and RCD testers cover a range of test functions, from basic earth fault loop impedance measurement through to comprehensive installation verification. Some of the types you’ll typically encounter include:

Earth Loop & Earth Fault Loop Testers

An earth fault loop tester measures the impedance of the earth fault loop path in an electrical installation, confirming that sufficient fault current will flow to operate the protective device within the required disconnection time.

The tester injects a test current between the live and earth conductors and measures the resulting impedance value. This is a fundamental test for any new or modified installation. It’s also required to demonstrate compliance with electrical safety regulations across commercial, industrial, and residential sites in Hong Kong.

Non-Trip Loop Testers

A non-trip electrical loop tester uses a low test current to measure earth fault loop impedance without triggering the RCD protecting the circuit. This is useful when testing live circuits in occupied buildings, healthcare facilities, and commercial premises where interrupting the power supply would be disruptive or unsafe. Non-trip loop tester technology allows the earth loop impedance tester to deliver accurate results without the downtime associated with tripping and resetting protective devices.

RCD Testers

An RCD tester verifies that a residual current device trips correctly when exposed to a fault current, confirming both the trip time and the trip current threshold. Testing covers RCD types including AC, A, and DC variants depending on the installation.

A dedicated RCD tester is also essential wherever RCDs form part of the circuit protection strategy. This ensures that the device will respond as required during a fault condition rather than failing.

Multifunction Testers with Loop & RCD

A multifunction tester combines loop impedance testing, RCD testing, insulation resistance measurement, continuity testing, and voltage measurement in a single instrument. These combined units are suitable for electricians and inspection teams who need to carry out full installation testing without the need for multiple separate instruments on site.

Models in the RS Hong Kong range cover loop impedance and RCD combined testing at voltages up to 1,000V, supporting both standard and higher-voltage installation verification.

Applications of Loop & RCD Testers

Loop and RCD testers support electrical safety and compliance across a wide range of environments, such as:

Electrical Installation & Compliance Testing

During new installations, rewiring, and commissioning work, an earth fault loop impedance tester confirms that each circuit meets disconnection time requirements before sign-off. Remember to compare different model and price options across our range to equip your teams cost-effectively while maintaining compliance documentation standards.

Industrial & Commercial Facilities

In factories, plant rooms, data centres, and commercial buildings, loop and RCD testers verify the protection of high-current circuits and distribution boards. Industrial environments often introduce electrical noise. As such, it’s important to select a loop impedance tester with adequate noise filtering and a voltage range suited to the system under test.

Electrical Maintenance & Fault Finding

Maintenance teams use loop testers to diagnose faults and identify hazards in existing circuits by measuring loop impedance and prospective fault current. An induction loop tester is also used to verify signal strength and loop performance in audio-frequency induction loop systems installed in public venues and commercial spaces across Hong Kong.

Residential Inspection & Safety Testing

Periodic residential inspection helps identify wiring deterioration, inadequate earthing, and RCD faults early. A non-trip electrical loop tester is well-suited to occupied properties. It measures earth fault loop impedance on RCD-protected circuits without interrupting power to residents.

Buy Loop & RCD Testers from RS Hong Kong

RS Hong Kong is a trusted loop tester supplier stocking a comprehensive range of products from leading brands including Megger, Gossen Metrawatt, Kewtech Corporation, and RS PRO. Whether you need a standalone earth fault loop tester or a combined loop impedance and RCD unit, our range covers every professional requirement.

Browse and order online at any time, or call our team on 852 2421 9898 for assistance. You can also consolidate your order by adding other items such as clamp meters, earth testers, and PAT testers in a single transaction.

Purchase today and enjoy fast delivery across Hong Kong. For delivery services and fees, visit our Delivery page.