Description

STU series travel voltage converter 100VA–3000VA

Sockets optional, single or double
Carrying handle on all frames up to this rating
Input voltage selector
ON/OFF switch
Fuse and MCB protection
Warranty: twelve months from delivery

Functions

Automatic, bidirectional conversion between 110–120V and 220–240V supplies.
Input tap matched to the local grid so output stays close to the rated figure.
Selector covers 110V, 120V, 220V and 240V; custom voltages available.
Output through the on-board socket, with a USB outlet rated 5A.
Intended for control panels, HVAC controls, lighting circuits, test benches and light industrial machinery.

Model	Capacity	Package Size(cm)	Qty/Package
STU-100	100W	41.5×27×38	12PCS
STU-200	200W	41.5×27×38	12PCS
STU-300	300W	48×29×41	12PCS
STU-500	500W	48×29×41	12PCS
STU-750	750W	48×29×41	12PCS
STU-1000	1000W	49.5×33×21	2PCS
STU-1500	1500W	49.5×33×21	2PCS
STU-2000	2000W	49.5×33×21	2PCS
STU-3000	3000W	54.5×33×24.5	2PCS
STU-4000	4000w	54.5×33×24.5	2PCS
STU-5000	5000W	54.5×33×24.5	2PCS
STU-7500	7500W	42.5×33×28	1PCS
STU-10000	10000W	42.5×33×28	1PCS

The STU‑series travel voltage converter is a heavy‑duty AC transformer designed for industrial and commercial environments that require safe, reliable voltage conversion for equipment used in different regions. Ranging from 100VA to 3000VA, the STU series supports a wide variety of input/output voltage combinations, making it ideal for industrial users, commercial facilities, electrical contractors, and electrical distribution networks.

These converters are commonly used to power control panels, HVAC systems, lighting controls, test equipment, and small industrial machinery that must operate on local grid voltages while maintaining strict safety and efficiency standards. Built with robust cores, high‑grade windings, and overload protection, the STU series ensures stable output, low noise, and long‑term reliability in 24/7 applications.

JOHsunTECH supplies the best travel voltage converter in the STU line as a manufacturer, factory, and OEM/ODM solution provider. We support distributors and wholesale partners with low MOQ, flexible configuration options, and custom labeling or design to meet your regional and brand requirements—all at competitive wholesale pricing.

■ How to Choose This Transformer

This configuration is specified by buyers who need a converter that survives continuous commercial use rather than occasional travel, so the deciding factor is duty cycle rather than peak wattage. For 24/7 duty we recommend operating at no more than 70 % of the nameplate figure — about 2,100W on a 3000VA frame — which leaves headroom for the ambient rise inside a panel or cabinet. If the unit will be installed in an enclosure rather than in free air, derate further and add forced ventilation.

Three points to confirm before ordering:

the continuous and peak load, and how many hours a day the unit will run;
the socket standard for your market and whether one or two sockets are required;
whether the unit will sit in free air or inside a control cabinet.

■ Applications in Practice

Control panels, HVAC control circuits, lighting controls, test benches and small industrial machinery that has to operate on a mains voltage different from the building supply. The common thread is that the equipment runs for hours at a time, so an under-built converter would overheat. Because these units are passive, they inject no high-frequency switching noise into a panel and do not need an EMC filter to coexist with analogue signal wiring.

■ Pricing, Ordering & Quality Assurance

Step Up & Step Down Transformer Price Range (100VA–10KVA)

Pricing for the DT/ST series depends on capacity, the input/output voltage combination you need, socket type, and whether a voltage selector or MCB protection is fitted. The table below gives indicative FOB levels so you can budget before requesting a firm quotation.

Model	Capacity	Input / Output Voltage	Typical Application	Indicative FOB Price (per pc)*
ST/DT-100	100VA	110V ↔ 220V selectable	Small electronics, chargers, control circuits	US$ 10–15
ST/DT-200	200VA	110V ↔ 220V selectable	Bench instruments, small appliances	US$ 11–16
ST/DT-300	300VA	110V ↔ 220V selectable	Audio equipment, laboratory benches	US$ 12-18
ST/DT-500	500VA	110V ↔ 220V selectable	Refrigeration units, printers, POS systems	US$ 12-20
ST/DT-1000	1000VA	110V ↔ 220V selectable	Power tools, kitchen equipment, single machines	US$ 21-30
ST/DT-1500	1500VA	110V ↔ 220V selectable	Motor-driven machines, imported appliances	US$ 23-35
ST/DT-2000	2000VA	110V ↔ 220V selectable	Compressors, welders, multi-outlet benches	US$ 25-37
ST/DT-3000	3000VA	110V ↔ 220V selectable	Small production lines, test rigs	US$ 33-43
ST/DT-5000	5000VA	110V ↔ 220V selectable	HVAC, industrial machinery	US$ 52-62
ST/DT-7500	7500VA	110V ↔ 220V selectable	Heavy workshop loads	US$ 75-87
ST/DT-10000	10000VA	110V ↔ 220V selectable	CNC equipment, whole-panel supply	US$ 85-112

* Indicative FOB Ningbo/Shanghai, standard configuration, based on 50 pcs per size. Not a formal offer — final price depends on your voltage combination, socket standard, enclosure and order quantity.

The efficiency of the DT/ST series is 80%. For equipment with motors or compressors, the starting current will multiply — always reserve adequate power margin.
Pure resistive / electronic loads: choose a transformer with capacity ≥ 1.5× the equipment rated power.
Inductive loads such as motors and compressors: choose a transformer with capacity ≥ 2.5–3× the equipment rated power.
This table is for reference only. Confirm the final solution according to the rated power and duty cycle shown on your equipment nameplate.

MOQ, Lead Time & Ordering Information

Minimum Order Quantity (MOQ)	1 PC for standard DT models. Smaller trial orders can be discussed for first-time buyers.
Custom / OEM orders	50 PCS for custom voltage, custom socket layout, branded front panel or non-standard capacity.
Sample	1-2 pcs sample available for verified buyers. Sample lead time 3-5 working days.
Lead time	10-20 working days for standard models after order confirmation and deposit; 15-25 working days for OEM or custom configurations.
Packing	Export carton with foam. 1/2/6 pcs per carton – see the packing table above.
Payment terms	100% TT IN ADVANCE FOR RETAIL/SAMPLE; 30% TT IN ADVANCE AS DEPOSIT, THE BALANCE BEFORE SHIPMENT.
Shipping	FOB Ningbo. CIF and door-to-door available on request.
Warranty	12 MONTHS FROM DELIVERY DATE

Certifications & Quality Assurance

DT/ST series step up and step down transformers are produced under our ISO 9001 quality management system, and every unit is 100% function-tested before packing.

Certificates and routine test reports can be issued as PDF on request, for customs clearance, tender submissions or distributor onboarding.

■ FAQ

How long can this converter run continuously?

Indefinitely within rating. For continuous duty we recommend loading to no more than 70 % of the nameplate figure so the winding stays cool and service life is not shortened.

Is the output isolated from the input?

Yes. The STU range uses a double-wound core, so primary and secondary are galvanically separated rather than sharing a winding.

Does it need any maintenance?

Very little. Keep the ventilation slots clear of dust, check the fuse annually and re-torque the terminals at the two-year service interval. There are no fans, capacitors or firmware to service.

Can it be supplied with a custom voltage ratio?

Yes, both windings can be wound to a non-standard ratio. Production lead time for custom configurations is 15–25 working days against a minimum of fifty pieces.

Request Quote

Tell us your specifications, quantity, or application scenario and we will reply with a tailored quote.

Best Travel Voltage Converter STU Series 100VA–3000VA