Table des matières
What Is Single-Phase Dry Voltage Transformer？
A Single-Phase Dry Voltage Transformer is a type of voltage transformer that uses no liquid insulation — such as oil or ester fluids — to cool or insulate its internal components. Instead, it relies on solid insulation materials including cast resin (epoxy), vacuum-impregnated insulation, or high-grade polymer compounds to isolate the primary and secondary windings from each other and from the core.
Unlike traditional oil-immersed transformers, dry-type transformers are completely self-contained and do not require a sealed tank, conservator, or expansion vessel. This design eliminates the risk of oil leaks, fire hazards, and environmental contamination, making them the preferred choice for indoor installations, environmentally sensitive areas, and applications where safety and minimal maintenance are top priorities.
Working Conditions of the Single-Phase Dry Voltage Transformer
- Standard operating range: –5°C to +40°C (daily average ≤ +35°C)
- Short-term extreme: –10°C to +50°C
- Altitude de conception standard : ≤ 1 000 mètres au-dessus du niveau de la mer
- Maximum humidity: 95% (non-condensing) at +40°C
- From grounded metal surfaces: ≥ 30 mm (low voltage) / ≥ 50 mm (medium voltage)
Paramètres du produit
| Type | Rapport de tension nominale (kV) | Accuracy Class & Rated Output COSΦ=0.8 (lagging) (VA) | Power Frequency Withstand Voltage (kV) | |
| JDZ-1 | 0.2 | 0.5 | ||
| 380/100 | 5 | 5 | 3 | |
| 660/100 | 5 | 5 | 3 | |
| 690/100 | 5 | 5 | 3 | |
| 1140/100 | 5 | 5 | 3 | |
Why Choose ZHIMING's Single-Phase Dry Voltage Transformer?
Superior Cast Resin Insulation Technology
ZHIMING uses high-grade epoxy resin with inorganic silica filler, vacuum-cast under controlled conditions to eliminate voids and air pockets. This results in exceptionally high dielectric strength (typically >3.5 kV/mm), excellent moisture resistance, and outstanding thermal conductivity. Our cast resin insulation is self-extinguishing (UL94 V-0 rated) and provides superior protection against dust, humidity, and mild chemical exposure.
High Accuracy for Metering and Protection
We manufacture transformers with precision accuracy classes ranging from Class 0.2 (for revenue metering) to Class 3.0 (for general indication). Our Class 0.5 and Class 1.0 units are particularly popular for utility metering and protection relay applications. Every transformer is individually ratio-tested and phase-angle verified before leaving our factory, ensuring reliable voltage signals for your critical equipment.
Compact, Lightweight, and Easy to Install
Without the need for heavy oil tanks, ZHIMING's single-phase dry voltage transformers are significantly smaller and lighter than equivalent oil-filled units. Standard designs feature wall-mounting brackets or DIN-rail adapters, clearly labeled primary (H1-H2) and secondary (X1-X2) terminals, and IP20 finger-safe terminal covers (higher IP ratings available).
Environmentally Friendly and Fire Safe
Our dry transformers contain absolutely no liquid oil, dielectric fluids, or SF6 gas. This means there is no risk of oil leaks contaminating soil or groundwater, no fire propagation because the epoxy resin is flame-retardant and self-extinguishing, no need for special fire suppression systems or spill containment, and full compliance with green building standards and environmental regulations .
Low Maintenance and Long Service Life
Because there is no oil to test, filter, or replace, ZHIMING's single-phase dry voltage transformers require minimal routine maintenance. Periodic visual inspection (every 12–24 months) for dust accumulation and terminal tightness is typically sufficient. The cast resin insulation is highly resistant to aging, moisture ingress, and partial discharge, giving our transformers an expected service life of 25+ years under normal operating conditions. This translates to significantly lower total cost of ownership compared to oil-filled alternatives.
FAQ
What is the main advantage of a dry-type voltage transformer over an oil-immersed one?
The primary advantages are safety et environmental compliance. Dry transformers contain no flammable oil, eliminating fire risk and eliminating the need for spill containment, fire vaults, or oil disposal. They are also maintenance-friendly — no oil testing, filtering, or replacement is required. This makes them ideal for indoor installations, occupied buildings, and environmentally sensitive sites.
Can ZHIMING's single-phase dry voltage transformers be used outdoors?
Standard IP20 units are designed for indoor, dry locations only. For outdoor or damp environments, ZHIMING offers weather-protected versions with IP54 (dust-tight and splash-proof) or IP65 (dust-tight and water-jet proof) enclosures, along with UV-stabilized finishes and anti-corrosion hardware. Please specify outdoor requirements at the time of ordering.
What accuracy classes do you offer, and which one do I need?
We offer Classes 0.2, 0.5, 1.0, et 3.0 per IEC 61869-3.
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Class 0.2: Revenue metering, export/import energy measurement, high-accuracy monitoring
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Class 0.5: Standard utility metering, most protection relays, general energy management
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Class 1.0: Indication only, backup protection, non-critical monitoring
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Class 3.0: Basic voltage presence indication, legacy systems
Most customers select Class 0.5 for the best balance of cost and accuracy.
How do I determine the correct VA burden for my application?
Add the VA consumption of all devices connected to the secondary winding (meters, relays, transducers, etc.). Then add a 25–50% safety margin to account for future additions and long cable runs. ZHIMING standard units are available from 10 VA to 500 VA. For burdens exceeding 500 VA, we offer custom designs. If uncertain, consult our engineering team with your device specifications.
What is the typical lifespan, and what maintenance is required?
Under normal working conditions, ZHIMING’s single-phase dry voltage transformers have an expected service life of 25+ years.
