TMG-100 100 kVA 10/0.4 kV transformer (S13-M-100)

TMG-100 (S13-M-100) technical data

Rated current and permissible load

Losses, efficiency and comparison with amorphous SH15

The amorphous-alloy core of the SH15 cuts the no-load loss by 50 % compared with the S13. For one 100 kVA transformer this saves about 657 kWh per year, because no-load loss is present the whole time the transformer is energised, regardless of the load.

Where a 100 kVA transformer is used

A 100 kVA transformer is typically chosen for sites with a design load of a few tens of kilowatts. On farms and in greenhouses it usually supplies ventilation, heating and lighting; at pumping stations, the pump motors and their control panels; in small shops and workshops, lighting, refrigeration and machine tools; at mobile telecom base stations, rectifiers and air conditioning. The sealed corrugated tank with vacuum oil filling suits such sites, which often operate without permanent staff.

• Farms and livestock facilities
• Greenhouses with lighting and climate control
• Irrigation and water-supply pumping stations
• Small shops, workshops and production units
• Mobile telecom base stations
• Rural 10/0.4 kV distribution networks

How to choose a TMG-100

For continuous duty, a loading of 70–80% is a sound target for the TMG-100 (S13-M-100): that is 63–72 kW at cos φ 0.9, leaving headroom for pump motor starting currents and seasonal peaks such as greenhouse supplementary lighting. If the design load fits within 70–80% of the TMG-63 rating, the smaller unit is sufficient and will run in its working range. If the expected load exceeds 72 kW or the site is likely to grow (more pumps, additional greenhouses, a second workshop line), it makes sense to install a TMG-160 from the start rather than replace the transformer a few years later.

Yyn0 is the traditional choice where the load is spread evenly across the phases and the neutral is lightly loaded. At sites typically fed by a 100 kVA transformer the picture is often different: single-phase consumers such as lighting, household appliances, controllers and the UPS units of base stations create phase unbalance and third harmonics. Dyn11 copes better with this kind of load and gives a larger single-phase fault current, which helps protective devices trip reliably on long 0.4 kV feeders. The load losses of the TMG-100 are 1580 W with Dyn11 and 1500 W with Yyn0.

No-load loss is independent of the load and is incurred for all 8760 hours of the year: 150 W or 1314 kWh per year for the S13-M-100, against 75 W and 657 kWh for the amorphous-core SH15-M-100. Where average loading is low or seasonal, as with irrigation pumps, off-season greenhouses or standby supplies, consider SH15, which is Dyn11 as standard; with a three-phase three-limb core, the Yyn0 vector group can also be supplied on request, so state it in your inquiry if you need it. Under high, steady loading the load loss, identical for S13 and SH15 in Dyn11 (1580 W), dominates, and S13 remains a rational choice. Where lower losses than S13 are needed at high loading, choose the energy-efficient S22-M-NX1 series; its 100 kVA version holds a type-test certificate.

Compact substation with a 100 kVA transformer

The 100 kVA transformer is also supplied as part of a compact substation: ZGS American-type pad-mounted substation (KTPN), up to 1600 kVA, or YB European-type substation (BKTP / GKTP), up to 2500 kVA. The substation is assembled and tested at the factory, so the site work mainly comes down to setting it in place and connecting the cables.

Other TMG (S13) ratings