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Mercury 230V to 120V Step Down Converter 300W - UK to USA Voltage Converter

£4099
The RRP is the manufacturer's recommended retail price of the item.
Limited Stock
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Description

The Mercury 651.031UK is a 300W step down converter that transforms UK 230-240V mains supply into USA-standard 110-120V output, allowing American appliances to run on British electrical infrastructure. Built around a transformer rather than electronic switching, the unit handles resistive and inductive loads up to 300W including audio equipment, small power tools, vintage electronics and household devices designed for US voltage.

Designed for workshop, studio and home use where US-specification equipment needs to operate on UK mains, the converter sits on a desktop or bench and connects via the supplied 3-core UK mains lead. The front panel houses a red neon-lit rocker switch for on/off control, a T2A fuse holder for overcurrent protection, and a US-style 2-pin output socket. The carry handle moulded into the top surface allows the 3.25kg unit to be moved between locations without strain.

The transformer-based design means the converter produces a true sinusoidal 120V output identical to US grid power, making it compatible with equipment that rejects the stepped waveforms from electronic converters — this includes some audio gear, vintage valve amplifiers and motors. The vented black ABS case dissipates heat from the transformer windings during continuous use, and the rubber feet prevent the unit sliding on smooth surfaces under cable tension.

Specification
Input 240Vac
Output 120Vac
Power max. 300W
Dimensions 198 x 136 x 101mm
Weight 3.25kg
Fuse T2A
Downloads

Product Manual

Frequently Asked

What appliances can this power?

Any US-voltage device rated up to 300W that expects 110-120V input. Common applications include small audio mixers, vintage radios, record players, desk fans, laptop chargers rated for 110V, and workshop tools. Check the device's power rating before connecting — watts = volts × amps, so a 120V device drawing 2.5A consumes 300W and sits at the converter's limit.

Can it run devices with motors or transformers?

Yes. The transformer-based design produces a clean sinusoidal waveform identical to US grid power, making it compatible with inductive loads like motors, transformers and vintage valve equipment that may not operate correctly on electronic switching converters.

Does it work in reverse to convert 120V to 230V?

No. This is a step-down converter only, designed to reduce UK 230-240V mains to US 110-120V. Using it in reverse would damage the unit and void any warranty.

What does the T2A fuse protect against?

The T2A (2 amp time-delay) fuse on the front panel protects the converter and connected device from overcurrent faults. If a connected device draws more than 300W or develops a short circuit, the fuse will blow and can be replaced without opening the case.

Shipping & Returns

Delivery UK delivery is £14.99, and delivery is free on all orders of £99 or more, in the UK and internationally.

Returns If you change your mind, you have 14 days from delivery to tell us, and a further 14 days to send the goods back. Return postage for a change-of-mind return is paid by you. Change-of-mind returns are subject to an inspection and handling deduction. See our full returns policy.

To arrange a return, call us on 020 8149 5199 or use our contact page.

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    Description

    The Mercury 651.031UK is a 300W step down converter that transforms UK 230-240V mains supply into USA-standard 110-120V output, allowing American appliances to run on British electrical infrastructure. Built around a transformer rather than electronic switching, the unit handles resistive and inductive loads up to 300W including audio equipment, small power tools, vintage electronics and household devices designed for US voltage.

    Designed for workshop, studio and home use where US-specification equipment needs to operate on UK mains, the converter sits on a desktop or bench and connects via the supplied 3-core UK mains lead. The front panel houses a red neon-lit rocker switch for on/off control, a T2A fuse holder for overcurrent protection, and a US-style 2-pin output socket. The carry handle moulded into the top surface allows the 3.25kg unit to be moved between locations without strain.

    The transformer-based design means the converter produces a true sinusoidal 120V output identical to US grid power, making it compatible with equipment that rejects the stepped waveforms from electronic converters — this includes some audio gear, vintage valve amplifiers and motors. The vented black ABS case dissipates heat from the transformer windings during continuous use, and the rubber feet prevent the unit sliding on smooth surfaces under cable tension.

    Specification
    Input 240Vac
    Output 120Vac
    Power max. 300W
    Dimensions 198 x 136 x 101mm
    Weight 3.25kg
    Fuse T2A
    Downloads

    Product Manual

    Frequently Asked

    What appliances can this power?

    Any US-voltage device rated up to 300W that expects 110-120V input. Common applications include small audio mixers, vintage radios, record players, desk fans, laptop chargers rated for 110V, and workshop tools. Check the device's power rating before connecting — watts = volts × amps, so a 120V device drawing 2.5A consumes 300W and sits at the converter's limit.

    Can it run devices with motors or transformers?

    Yes. The transformer-based design produces a clean sinusoidal waveform identical to US grid power, making it compatible with inductive loads like motors, transformers and vintage valve equipment that may not operate correctly on electronic switching converters.

    Does it work in reverse to convert 120V to 230V?

    No. This is a step-down converter only, designed to reduce UK 230-240V mains to US 110-120V. Using it in reverse would damage the unit and void any warranty.

    What does the T2A fuse protect against?

    The T2A (2 amp time-delay) fuse on the front panel protects the converter and connected device from overcurrent faults. If a connected device draws more than 300W or develops a short circuit, the fuse will blow and can be replaced without opening the case.

    Shipping & Returns

    Delivery UK delivery is £14.99, and delivery is free on all orders of £99 or more, in the UK and internationally.

    Returns If you change your mind, you have 14 days from delivery to tell us, and a further 14 days to send the goods back. Return postage for a change-of-mind return is paid by you. Change-of-mind returns are subject to an inspection and handling deduction. See our full returns policy.

    To arrange a return, call us on 020 8149 5199 or use our contact page.