Two-storey E-House at the Ninghai 35 kV substation with a blue Sieyuan band and steel stairs up to the upper walkway

Ninghai 35 kV Substation E-⁠House: Two Storeys, Eight Modules

Ninghai Shepantu 35 kV Power Supply Project|China & East Asia

Ninghai Zhejiang

35 kV substation

Eight modules

5 lower + 3 upper

Sieyuan Electric

OEM in its livery

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Project Overview

Power & GridOct 2026China & East Asia

ETENZ manufactured the two-storey E-House for a 35 kV prefabricated substation at Shepantu in Ninghai County, Zhejiang, China, and supplied it to Sieyuan Electric, the project's EPC contractor. Eight modules make up the building: the five on the lower level form the 35 kV and 10 kV switchgear rooms, and the three on the upper level hold the protection and control room and the 10 kV capacitor bank room. The lower level measures 12 × 7.5 m, the 9 × 7.5 m upper level stands on top of it, each level is 3.6 m high, and the equipment rooms add up to 157.5 m². The substation belongs to the Ninghai County Shepantu 35 kV power supply line project. ETENZ painted the E-House in Sieyuan Electric's livery and delivered it to site in October 2026. The modules have been joined on site, and equipment commissioning is now under way.

Ninghai 35 kV substation: oil-immersed main transformer in front of the two-storey E-House, transmission tower behind

Service Scope

Two-Storey E-⁠House Manufacturing and Auxiliary Systems (OEM for Sieyuan Electric)

ETENZ designed, manufactured and joined on site all eight modules, and fitted them out with the lighting, power and maintenance distribution and the earthing system; wall-mounted industrial air conditioners, axial exhaust fans and motorized intake dampers; insulating rubber mats along the inspection aisles of the switchgear rooms and ceramic anti-static flooring on the upper level; and two access stairs, a caged ladder and the guardrails of the upper-level walkway. ETENZ also painted the building in Sieyuan Electric's livery. The 35 kV and 10 kV switchgear, secondary panels and capacitor cabinets are Sieyuan Electric's equipment, and ETENZ worked with Sieyuan on installing them in the modules.

10 kV switchgear room on the lower level: facing switchgear line-ups marked with bay names, aisle between them

Engineering & Integration

Switchgear Below, Control and Capacitors Above

The 35 kV and 10 kV switchgear is heavy and carries many incoming and outgoing cables, so it occupies the five lower modules; the protection and control room and the 10 kV capacitor bank room take the three upper modules. The lower level includes a cable shaft, and the cable openings and spare panel positions between the levels are closed with cover plates before the modules leave the factory, to be opened on site as needed.

Eight Factory-Built Modules, Stacked Into Two Levels on Site

Each of the eight modules was built separately in the factory. On site, the lower level was joined first and the upper level was then stacked on top, with every module seam waterproofed. The frames are welded integral structures of steel sections; the roof, outer walls and doors are 2.0 mm steel plate, and the interior floor plate is 3 mm.

Access Stairs, Upper Walkway and Roof Ladder

The two access stairs are built at a 45° pitch with step spacing of 200 to 255 mm. The upper-level walkway is laid with WPC decking behind 1.2 m guardrails, the upper level has doors that open both ways, and a caged ladder on the upper roof gives maintenance access.

Insulated Walls and Indoor Climate Control

The 150 mm walls combine a rock wool fill with a polyurethane foam layer, and the roof is insulated as well, so the building is insulated on five sides. The two switchgear rooms and the protection and control room share five wall-mounted industrial air conditioners together with axial exhaust fans; in the 35 kV switchgear room, the motorized intake dampers open and close in step with the exhaust fans.

End of the E-House: steel stairs to the upper walkway with WPC decking, blue guardrails and a caged roof ladder

Delivery Outcome

The two-storey E-House reached site in October 2026 and its modules have been joined. The switchgear, secondary panels and capacitor cabinets are in place inside, and commissioning is under way on site. ETENZ delivered the complete building on an OEM basis in Sieyuan Electric's livery.

Modules

Five on the lower level and three on the upper level, forming one two-storey E-⁠House

90 m²

E-House footprint

Lower level 12 × 7.5 m with the 9 × 7.5 m upper level on top; 157.5 m² of equipment rooms in total

35 kV

Substation served

Ninghai County Shepantu 35 kV power supply line project

Project Value

Stacking two levels puts 157.5 m² of equipment rooms on a 90 m² footprint, which suits substations and switching stations where land is scarce. ETENZ builds the enclosure to the EPC contractor's technical agreement and brand identity and fits out the auxiliary systems inside, offering OEM delivery to grid EPC contractors and switchgear manufacturers.

Aerial view of the two-storey E-House: secondary equipment level stacked on the primary equipment level, ponds behind

Project Facts

Enclosure protection	IP55
Ambient temperature	-8.5 to 39.5 °C
Maximum wind speed	35 m/⁠s
Ice thickness	30 mm
Seismic intensity	8 (0.3 g)
Delivery	October 2026