Distribution transformers for Peru

Medium voltage in use

The FONAFE specification is a 2017 edition published by one of the group’s companies. Confirm with your own utility which of these it uses.

Low voltage and frequency

• Frequency: 60 Hz nominal (National Electrical Code – Utilisation, rule 020-502).
• Public low-voltage networks: 380/220 V three-phase four-wire with the neutral effectively earthed is the recommended system; existing voltage levels may continue in use (rule 020-500).
• The FONAFE transformer specification lists secondaries of 0.40–0.231 kV, 0.46–0.23 kV and 0.231 kV, depending on the item.

Construction details in the FONAFE specification

• Altitude: designed for 0 to 4500 m above sea level; ambient −15 to 40 °C, relative humidity up to 99 %. The insulation levels are set for the full altitude range.
• Cooling ONAN or KNAN; winding temperature rise 65 °C; outdoor mounting.
• Tapping ±2 × 2.5 % on dual-primary units, which must meet the loss tables at both primary voltages.
• Vector groups in the specification: Dyn5 and Yyn6 (star secondary), Dd6 and Yd7 (delta secondary), depending on the primary voltage and item.
• Short-circuit impedance 4 % for three-phase units of 15 to 630 kVA.
• Standards named: IEC 60076-1 and Peruvian NTP 370.400 (distribution transformers: no-load current, losses and short-circuit voltage).
• Insulation level examples: 10 kV equipment 75 kV impulse; 13.2 kV 95 kV; 22.9 kV 125 kV.

Maximum losses in the specification (three-phase)

Values from the NTP 370.400 tables as reproduced in the specification; they already include the IEC 60076-1 tolerances. Bidders must state losses as percent of rated power and in watts.

Certification

We did not find a Peruvian regulation that places distribution transformers under mandatory product certification. Tenders from the state-owned distribution companies ask the bidder to state the manufacturing standard (IEC 60076-1, NTP 370.400) and to fill in the guaranteed-data sheet. Ask the utility or your tender documents whether any certificate, test report or approved-manufacturer requirement applies.

What our published ratings cover

• Oil-immersed S11: published for 6 / 6.3 / 10 / 10.5 / 11 kV (30–4500 kVA) and 20 kV (30–1600 kVA); LV 380, 400, 415 and 433 V; tapping ±2 × 2.5 %; IEC 60076. The published loss values are 50 Hz guarantees. 60 Hz units for Peru are designed and quoted per order.
• 22.9 kV and 13.2 kV primaries, dual-primary windings, 0.40–0.231 kV and 0.46–0.23 kV secondaries, Dyn5 / Yyn6 / Dd6 / Yd7 vector groups, and the altitude and loss requirements of the specification: on request.
• Pad-mounted transformers are IEEE/ANSI C57.12 at 60 Hz; their published HV list (up to 19.92 kV) does not include 10 kV or 22.9 kV, and the published LV options do not include 380/220 V, so a Peruvian pad-mounted unit is quoted on request.

Send with your enquiry

• Utility or project and site (city, altitude in metres above sea level)
• Rated power (kVA), primary voltage or voltages (10, 13.2, 22.9 kV, or dual), secondary (for example 380/220 V or 400/231 V)
• Vector group and tapping range; single- or three-phase
• Loss limits or the standard they come from (for example NTP 370.400), and any guaranteed-data sheet to be filled in
• Quantity and required delivery date