Martindale BZ101 Buzz-It Review: A Reliable Caravan Socket Tester for UK and European Touring
- Caravan Coach
- 4 hours ago
- 5 min read
Product Category: Electrical Test Equipment / Socket Testers
Brand: Martindale Electric
Prices Usually Range From: £15 - £23
Best For: Caravanners who want quick verification of EHU connections, especially when travelling to European sites where reversed polarity is common
Where to Buy: Available at RS Components, Test-Meter.co.uk, Rapid Electronics, or major retailers like Amazon
Caravan Socket Tester - Introduction
Plugging into an electric hook-up without knowing whether the supply is safe is a risk many caravanners take without realising it. Faulty wiring at a site bollard, a damaged EHU cable, or reversed polarity on a continental pitch can all create hazards that are invisible until something goes wrong. The Martindale BZ101 Buzz-It socket tester is a straightforward tool that removes the uncertainty of caravan hook-ups in seconds.
Martindale Electric have been making test equipment since 1928 and pioneered the original socket tester concept. The BZ101 builds on their classic CP501 check plug by adding an audible buzzer that sounds when wiring is correct. This feature proves particularly useful when testing sockets in awkward positions, such as behind furniture or in the confined spaces typical of caravan interiors, where seeing the LED indicators can be difficult.
For caravanners heading to France, Germany, or other European destinations, the BZ101 becomes even more valuable. Reversed polarity occurs on roughly one in ten continental sites, particularly in rural areas. While your appliances will still function with reversed polarity, the safety implications are significant. UK caravans use single-pole switching, which means that if the polarity is reversed, your appliances may remain live even when switched off. The BZ101 quickly identifies this condition, allowing you to use a polarity reversal adapter before connecting your caravan. If you prefer a contactless approach for quick power detection, you might also find a non-contact voltage tester useful for initial diagnosis before more detailed testing.
Key Features
The BZ101 detects 28 different wiring fault conditions through a combination of three bright LED indicators and an audible buzzer. When all three LEDs illuminate and the continuous tone sounds, the socket is correctly wired. Any deviation from this pattern indicates a fault, with common conditions such as live-neutral reversal, missing earth, neutral fault, and live-earth reversal clearly indicated through different LED combinations. A reference chart printed directly on the plug body makes interpreting results straightforward, with additional fault codes listed in the included instruction card.
The audible buzzer provides immediate confirmation without needing to look at the unit. This proves invaluable when testing sockets positioned behind the caravan's fridge, under benches, or in other locations where direct line of sight is limited. The buzzer is loud enough to hear clearly from several metres away, making it practical for checking multiple sockets from a central position.
An additional function allows the BZ101 to work as a basic fuse finder. When plugged into a live, correctly-wired socket, the buzzer sounds continuously. By switching off circuit breakers or removing fuses at the consumer unit one at a time, you can identify which circuit feeds a particular socket. When the correct fuse is pulled, the buzzer stops. This feature saves time when troubleshooting caravan electrical systems or identifying which circuit protects specific sockets.
The tough, sculpted ABS housing provides a secure grip and makes removal from tight sockets easier. The flame-retardant plastic construction meets BS EN 61010-1 safety standards and is rated CAT IV 300V. The compact dimensions of 65 x 65 x 47mm mean the BZ101 takes up minimal space in your electrical accessories bag.
Pros and Cons
Pros:
Audible buzzer confirms correct wiring without needing to see the LEDs, ideal for testing sockets in awkward positions
Detects 28 fault conditions with clear LED indication patterns
Doubles as a fuse finder for troubleshooting electrical circuits
Compact size stores easily with EHU equipment
Trusted brand with over 90 years of test equipment experience
No batteries required as it draws power from the mains supply
Excellent value compared to more complex testing equipment
Cons:
Cannot detect earth-neutral reversal or common earth-neutral faults (limitation shared by all standard socket testers)
No RCD test function (available on higher-spec models such as the EZ365)
Performance
In practical use, the BZ101 delivers exactly what it promises. Plug it into any 13A socket in your caravan and you have instant confirmation of correct wiring or clear indication of any fault condition. The response is immediate with no warm-up time required. The buzzer volume is pitched at a level that is easily audible without being startling, and the tone is distinctive enough to hear over background noise.
The LED indicators use long-life neon technology that provides bright, clear visibility even in daylight. The reference chart on the plug face covers the most common fault conditions at a glance, with the full 28-fault matrix available on the instruction card. Most users find the visual pattern recognition becomes intuitive after just a few uses.
Professional electricians regularly use the BZ101 for quick first-line testing, which speaks to its reliability. User feedback consistently highlights how it has identified genuine faults, including loose connections that presented potential fire risks, faulty site bollards, and damaged EHU cables. Several users have reported finding reversed polarity on continental sites exactly as expected, confirming the value of carrying this tool when travelling abroad.
Build quality matches the professional heritage of Martindale products. The housing feels solid without unnecessary bulk, and the pin design ensures secure contact in both new and older sockets. The two-year warranty provides additional confidence, though the straightforward construction suggests longevity well beyond this period with reasonable care.
Specifications
Operating Voltage: 230V AC
Frequency Range: 30-70Hz
Power Consumption: Less than 3W
Safety Rating: CAT IV 300V
Operating Temperature: -10°C to 40°C
Fault Detection: 28 wiring conditions
Indication: Three LED indicators plus audible buzzer
Dimensions: 65 x 65 x 47mm
Compliance: BS EN 61010-1
Housing: Flame-retardant ABS
Warranty: 2 years
Why It's Recommended
The Martindale BZ101 earns its place in the caravan electrical kit through a combination of simplicity, reliability, and genuine usefulness. It addresses a real safety concern without overcomplicating the solution. For UK touring, it provides peace of mind that site bollards and your caravan's internal wiring are functioning correctly. For European travel, it becomes genuinely essential for identifying reversed polarity before it creates a hazard.
The audible buzzer differentiates this model from basic socket testers and justifies the modest price premium over the non-buzzer CP501 version. Being able to hear confirmation of correct wiring when testing hard-to-see sockets makes the task quicker and more certain. The fuse-finding capability adds practical value for troubleshooting.
At current prices between £15 and £20, the BZ101 represents excellent value as part of your touring safety equipment. Pair it with a polarity reversal adapter for continental trips and you have the tools needed to ensure safe electrical connections wherever you pitch.
Rating
Overall Score: 4.5/5
Score Breakdown
Design: 4/5
Durability: 5/5
Ease of Use: 5/5
Value for Money: 4.5/5
Disclaimer
This review reflects our genuine opinions and experiences. Some of the links in this article are affiliate links, including Amazon Associate links. As an Amazon Associate, we earn from qualifying purchases. This means we may receive a small commission if you buy through these links, at no extra cost to you.
Product details, availability, and prices were accurate at the time of writing but may change without notice. Please check with the retailer for the latest information before making a purchase. Caravan Coach cannot be held responsible for differences between this review and the actual product or service you receive.
