Ingco HSDT1408 Voltage Test Pencil 100–500V AC (140mm

The Ingco test pencil is a compact voltage tester designed for basic AC checks across a 100–500V range, making it a practical site and toolbox essential.

Ideal for trade professionals, maintenance teams and DIY users, this screwdriver-style test pencil supports quick electrical checks before working on sockets, switches and wiring. Features neon bulb indication, slotted tip for dual functionality, and compact pocket-friendly design. Always follow safe working practices.

Key benefits

• AC voltage testing range: 100–500V for common electrical systems
• Screwdriver-style test pencil with slotted 3mm tip
• Neon bulb indicator provides clear visual voltage confirmation
• Compact 140mm length fits easily in toolbags, pockets, and tool belts
• Dual-function tool: voltage tester and small slotted screwdriver
• Low-cost essential add-on item for site work at £1.19
• Suitable for trade professionals and DIY applications
• Simple tool for basic electrical safety checks
• Lightweight and portable (approximately 100g)
• Durable high-quality construction
• Packed in plastic hanger for retail display and storage

Best for

• Quick voltage presence checks on AC circuits before work begins
• Testing sockets, outlets, switches, and light fixtures
• Identifying live wires and voltage presence in electrical installations
• Basic electrical maintenance tasks and fault finding
• Residential electrical work (120V/240V systems)
• Commercial and light industrial electrical testing
• Verifying circuits are de-energized before maintenance
• Emergency electrical troubleshooting
• Keeping as an affordable spare in toolboxes, vans, and site kits
• DIY home electrical projects and repairs

Key features – why it matters

• AC 100–500V voltage range: suitable for testing common residential (120V/240V), commercial, and light industrial AC electrical systems - covers the most frequently encountered voltage levels in everyday electrical work - provides reliable detection across entire range
• Screwdriver-style test pencil format: classic electrician's tool combines voltage testing with small screwdriver functionality - familiar design trusted by electricians worldwide - slim pen-style shape for convenient handling and storage
• Neon bulb visual indication: built-in neon bulb glows when voltage is detected - provides clear, unmistakable visual confirmation of live circuits - no batteries required (bulb operates from detected voltage) - simple and reliable indication method
• 3mm slotted tip (140mm length): slotted screwdriver tip allows dual functionality as voltage tester and small screwdriver for terminal screws, outlet covers, and electrical fittings - eliminates need to carry separate tool for minor adjustments - 3×140mm size (3mm tip width, 140mm overall length) is optimal for compact portability
• Compact 140mm length: pocket-friendly size fits easily in shirt pockets, tool bags, tool belts, and small storage compartments - always accessible when needed - doesn't take up valuable toolbox space
• No batteries required: neon bulb operates directly from detected AC voltage - always ready to use without battery concerns - eliminates ongoing battery replacement costs and dead battery failures
• Lightweight portable (100g): minimal weight makes it effortless to carry - can keep multiple units in different locations (van, toolbox, home) without burden
• Durable construction: high-quality materials ensure reliable performance in demanding work environments - built to withstand daily professional use
• Affordable essential (£1.19): extremely low cost makes it accessible for everyone - affordable enough to keep multiple units as backups or distribute to team members - exceptional value for essential safety tool
• Safe and reliable: designed for voltage testing safety - helps prevent electrical shock by identifying live circuits before physical contact
• Simple operation: intuitive use requires no training - touch tip to conductor while holding finger on metal cap - neon bulb lights if voltage present
• Plastic hanger packaging: convenient retail packaging with hanger for display and storage

Specifications

What's included

• 1 × Ingco AC 100–500V test pencil (HSDT1408)
• Plastic hanger packaging

How to use

• Follow electrical safety procedures: Always follow standard electrical safety practices including wearing appropriate personal protective equipment (PPE), assuming all circuits are live until proven otherwise, and following local electrical codes and regulations.
• Inspect test pencil before use: Check the test pencil for any physical damage, cracks in the insulation, or worn components. Do not use if damaged. Verify neon bulb is intact.
• Test on known live circuit first: Before relying on the test pencil, verify it's functioning properly by testing on a known energized circuit. The neon bulb should glow when detecting voltage, confirming the tool is operational.
• Hold test pencil correctly: Grip the insulated body of the test pencil. Place your finger or thumb on the metal cap or contact point at the top end of the pencil (this completes the circuit through your body to ground, allowing the neon bulb to light).
• Touch tip to conductor: Touch the slotted metal tip to the electrical conductor, terminal, or contact point you wish to test. For outlets, insert tip into outlet slot. For exposed wires or terminals, touch directly to conductor.
• Observe neon bulb indication: If AC voltage is present within the 100-500V range, the neon bulb inside the test pencil will glow/light up. No glow indicates absence of voltage (circuit is de-energized or voltage is outside detection range).
• Test multiple points: For thorough verification, test multiple points in the circuit (both slots of an outlet, multiple terminals, etc.) to ensure complete understanding of circuit status.
• Use screwdriver function when safe: Once voltage is confirmed absent, the slotted tip can be used as a small screwdriver for loosening/tightening terminal screws, outlet covers, and electrical fittings (3mm slotted applications).
• Confirm results appropriately: For critical applications or professional electrical work, confirm test pencil results using additional testing methods such as a multimeter or non-contact voltage detector.
• Never assume circuits are safe: Even if test pencil shows no voltage, follow proper lockout/tagout procedures and use appropriate verification methods before working on electrical systems.

Care & maintenance

• Keep the test pencil clean and dry at all times.
• Wipe with dry cloth to remove dust, dirt, and contaminants.
• Do not immerse in water or expose to moisture.
• Store in a tool case, organiser, or protective sleeve to protect the tip and body from damage.
• Inspect regularly for cracks, damage to insulation, worn tip, or broken neon bulb.
• Replace immediately if damaged, showing signs of wear, or if neon bulb no longer functions.
• Do not drop or subject to severe impact.
• Avoid exposure to extreme temperatures, chemicals, or solvents.
• Test regularly on known live circuits to verify proper operation.
• Do not attempt to repair or modify - replace if faulty.
• Keep away from children when not in use.
• Store in dry location away from moisture and corrosive environments.

Safety warnings

• Basic screening tool only: This test pencil is a basic voltage detection tool, not a comprehensive electrical testing instrument. Always use appropriate testing equipment and follow proper electrical safety procedures.
• Limited voltage range: Only detects AC voltage between 100-500V. Will not detect voltages below 100V (including many low-voltage circuits) or above 500V. Will not detect DC voltage.
• Not a precision instrument: Does not provide accurate voltage readings - only indicates presence or absence of voltage. Use multimeter for precise measurements.
• Requires body contact: Must complete circuit through your body to ground for neon bulb to light. This is inherent to the design but means you become part of the circuit.
• Always verify with additional methods: For critical applications, verify test pencil results with multimeter or other testing equipment.
• Assume all circuits are live: Never assume a circuit is safe based solely on this tool. Always follow lockout/tagout procedures.
• Wear appropriate PPE: Use insulated gloves, safety glasses, and other protective equipment when working with electrical systems.
• Qualified personnel only: Electrical work should only be performed by qualified personnel familiar with electrical safety.
• Follow local codes: Always comply with local electrical codes and regulations.
• Do not use if damaged: Replace immediately if cracked, damaged, or neon bulb is broken.
• Environmental limitations: May not function reliably in all conditions. Verify operation before critical use.

Accessories & add-ons

• Non-contact voltage detectors (VD100026) for safer contactless testing
• Digital multimeters for precise voltage, current, and resistance measurements
• Clamp meters for AC/DC current measurement
• Insulated screwdrivers and hand tools
• Wire strippers and cable cutters
• Electrical PPE (insulated gloves, safety glasses, arc flash protection)
• Tool belts and storage pouches
• Protective carrying cases for test equipment
• Additional test pencils for backup and multiple locations

Delivery & returns

Free UK delivery on orders over £50. 28-day returns apply.

Why buy from London Decorators Merchants

• Independent, family-owned business
• 16 decorating stores nationwide
• Trade-friendly service and support
• UK stock with fast dispatch
• Trade account available
• Expert advice on electrical testing tools

Add to basket or visit our branch for trade essentials.

FAQs

What voltage range does this test pencil cover?

This test pencil is designed for AC 100–500V checks. It detects alternating current voltage within this range, covering common residential (120V/240V), commercial, and light industrial electrical systems. It will not detect voltages below 100V or above 500V, and it does not work with DC (direct current) voltage.

Is this suitable for household electrics?

Yes, it can be used for basic AC voltage checks on household electrical systems including standard 120V and 240V circuits, outlets, switches, and light fixtures. However, safe working practices must always be followed, including wearing appropriate PPE, following local electrical codes, and verifying results with additional testing methods when appropriate. For comprehensive electrical work, use alongside proper testing equipment.

Is this a screwdriver-style voltage tester?

Yes, this is a classic screwdriver-style test pencil with a slotted 3mm tip. It combines voltage testing functionality with a small slotted screwdriver for dual-purpose use. The pen-style format with slotted tip allows you to test for voltage and also perform minor screwdriver tasks on terminal screws and outlet covers.

Does it need batteries?

No, this test pencil does not require batteries. The neon bulb indicator operates directly from the detected AC voltage in the circuit being tested. This means it's always ready to use without battery concerns, eliminates ongoing battery costs, and prevents dead battery failures. The neon bulb lights when voltage is present by using the electrical current from the circuit.

How long is the test pencil?

The test pencil measures 140mm in overall length with a 3mm slotted tip width (designated as 3×140mm). This compact size makes it easy to carry in shirt pockets, tool bags, and tool belts. The 140mm length provides adequate reach for most testing applications while remaining highly portable.

Is this suitable for trade use?

Yes, it is suitable for basic voltage checks in trade and DIY settings. Many electricians and tradespeople keep these affordable test pencils as quick screening tools and backups. However, for professional electrical work, it should be used alongside comprehensive testing equipment like multimeters and should follow proper electrical safety procedures. It's a reliable basic tool but not a replacement for precision testing instruments.

Is this a certified safety tester?

Specific safety certifications should be confirmed from the manufacturer or product packaging. While this is a quality electrical testing tool, it should be used as a basic screening device alongside proper electrical testing procedures and equipment. For critical safety applications, always follow applicable safety standards, use certified testing equipment, and comply with local electrical regulations.

Do you sell other electrical testing tools?

Yes. A range of voltage detectors (including non-contact models like VD100026), digital multimeters, clamp meters, and professional testing tools are available for comprehensive electrical testing and troubleshooting needs.

How does the neon bulb indication work?

The neon bulb inside the test pencil lights up (glows) when AC voltage is detected. To use it, you hold your finger on the metal cap at the top while touching the slotted tip to the conductor being tested. This completes the circuit through your body to ground. When voltage (100-500V AC) is present, a small current flows through the neon bulb, causing it to glow visibly. No glow means no voltage is detected.

Can I use this as a regular screwdriver?

Yes, the slotted 3mm tip can be used as a small screwdriver for terminal screws, outlet covers, and other 3mm slotted applications. However, only use the screwdriver function after confirming the circuit is de-energized. Never use as a screwdriver on live circuits. The primary function is voltage testing, with screwdriver use as a secondary convenience feature.

Will it detect low-voltage circuits?

No, this test pencil only detects AC voltage from 100V minimum. It will not detect low-voltage circuits below 100V such as 12V, 24V, or 48V systems commonly used in doorbells, thermostats, lighting transformers, and control circuits. For low-voltage testing, use a multimeter or specialized low-voltage detector like the VD100026 which detects from 12V.

Does it work on DC voltage?

No, this test pencil is designed exclusively for AC (alternating current) voltage detection from 100-500V. It will not detect DC (direct current) voltage. For DC voltage testing, use a digital multimeter with DC voltage measurement capability.

How do I know if it's working properly?

Before each use, test the pencil on a known live circuit (such as a working outlet) to verify the neon bulb lights up when voltage is present. This confirms the tool is functioning properly. If the neon bulb doesn't light on a known live circuit, the tool may be damaged or the neon bulb may be burned out - replace the test pencil immediately.

Is it safe to use?

When used properly according to instructions and standard electrical safety practices, test pencils are generally safe for basic voltage checks. However, they do require completing a circuit through your body to ground, which means you become part of the circuit. Always wear appropriate PPE, follow electrical safety procedures, and never rely solely on this tool for critical safety decisions. For enhanced safety, consider non-contact voltage detectors that don't require physical contact.

Why is it so inexpensive at £1.19?

The low price reflects the simple, proven design that's been used for decades. Test pencils use basic neon bulb technology with no batteries or complex electronics, making them very affordable to manufacture. Despite the low cost, they provide reliable basic voltage detection for everyday electrical work. The affordable price makes them practical to keep multiple units as backups or in different tool kits.

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