Description

This 45 kVA three phase transformer steps a 480 volt delta industrial supply down to 208Y/120 volts — the configuration that gives you 208 volts three phase for equipment and 120 volts single phase to neutral for lighting, receptacles and controls from the same transformer. It is NEMA 3R rated for outdoor installation, which is what makes it suitable for a container yard or an equipment compound rather than only a switchroom. Listed at $3,500.

45 kVA Transformer Specifications

Rating: 45 kVA
Phase: three phase
Primary: 480 V AC delta
Secondary: 208 V AC wye / 120 V
Function: step down
Frequency: 60 Hz
Winding material: aluminium
Temperature rise: 80°C
Enclosure rating: NEMA 3R, indoor/outdoor
Enclosure material: steel, ASA 61 grey
Includes: weathershield
Mounting: floor
Standards: UL 1561, CSA C22.2 No. 47 (file E12547, LR7357-32)
Reference: Acme Electric T3045K0013BSB
Price: $3,500

Why 208Y/120 Is the Useful Secondary

A 480 volt delta service is what industrial sites are fed with, and it is excellent for motors and heavy equipment and useless for anything else. There is no neutral, so there is no 120 volt for a light, a laptop, a battery charger or a control circuit. A 208Y/120 secondary provides both from one transformer: 208 volts three phase between phases for equipment, and 120 volts from any phase to the neutral for everything else. It is the standard answer for a site office, a workshop or a yard that has 480 volts at the fence and needs ordinary power inside it.

NEMA 3R and the Weathershield

NEMA 3R means the enclosure is rated to withstand rain, sleet and external ice formation — it can be installed outdoors on a pad without a building around it. The supplied weathershield covers the ventilation openings so that water cannot enter them while air can still circulate. A NEMA 1 transformer installed outdoors will be destroyed by the first serious rain; the two are not interchangeable.

Sizing

Add the full-load kVA of everything on the secondary, then leave headroom for motor starting inrush — a compressor or a pump draws several times its running current for the first seconds. Undersizing shows up as voltage sag on start and nuisance tripping, not as an immediate failure, so it is easy to get wrong and unpleasant to live with. If you are close to 45 kVA on paper, go up. Related: our 30 kVA 480 V to 240/120 V unit.

Efficiency Regulations

Transformers of 15 kVA and above are subject to DOE 2016 efficiency legislation, and units meeting it use more core material to cut no-load losses. On a transformer energised twenty-four hours a day, those standing losses are a permanent line on the electricity bill regardless of load, so the efficient unit repays its premium.

Freight

Floor-mounted and heavy; ships palletised with forklift loading. Freight is quoted to your delivery ZIP code. Contact us with your supply voltage and connected load and we will confirm the right unit before you order.