Station Post Insulators C4-125
C4-125 Station Post for Medium Voltage Busbar Support
C4-125 is a compact solid-core porcelain station post: 130 mm across the sheds, 305 mm tall, with 500 mm of creepage, a 4 kN cantilever strength and an 800 N-m torsion rating, weighing 6.6 kg. It is the medium voltage busbar and equipment support for indoor and outdoor switchgear, where loads are modest and space is tight.
Key Benefits
- 800 N-m torsion strength in a compact 305 mm post
- 500 mm creepage for medium voltage switchgear
- 6.6 kg per unit, easy to mount in enclosed panels
- 125 kV lightning impulse withstand voltage
Technical Features
- Solid-core porcelain, 130 mm shed diameter, 305 mm height
- 60 kV power-frequency dry and 50 kV wet withstand voltage
- 4 kN cantilever strength
- Grey or brown glaze
Published Figures for This Design
The values below are the catalogued figures for this type. Where a figure your specification needs is not listed, ask and we will confirm it in writing rather than estimate it.
| Available Colors | Grey, Brown |
|---|---|
| Diameter (D) | 130mm |
| Spacing (H) | 305mm |
| Creepage Distance | 500mm |
| Net Weight Each | 6.6kg |
| Cantilever Strength | 4kN |
|---|---|
| Torsion Strength | 800N-m |
| Power Frequency Dry Withstand Voltage | 60kV |
|---|---|
| Power Frequency Wet Withstand Voltage | 50kV |
| Lightning Impulse Withstand Voltage | 125kV |
Application Scenarios
- Medium voltage switchgear panel busbar support
- Outdoor pole-mounted switch bases
- Compact substation equipment supports
Who It Is For
- Switchgear panel builders
- Medium voltage equipment OEMs
- Utilities maintaining distribution substations
Problems It Solves
- Oversized posts that do not fit inside switchgear enclosures
- Creepage shortfalls in humid or dusty indoor substations
- Support insulators that loosen under repeated switch operation
How This Design Differs From the Alternatives
Compared With C6-170 station post
Smaller and lighter with 4 kN cantilever against 46 kN; use C4-125 for medium voltage panel work and C6-170 for outdoor busbars.
Compared With ANSI 57-2 line post
Designed for vertical equipment support rather than for carrying a conductor on a line structure.
Specifying and Installing This Unit
- Check the busbar short-circuit force against the 4 kN cantilever rating
- Allow clearance for the 130 mm shed diameter inside the enclosure
- Mount on a flat surface and tighten fixings evenly
- Clean the sheds during panel maintenance, since indoor dust reduces effective creepage
Questions About This Product
Is 4 kN cantilever enough for a switchgear busbar?
For most medium voltage panel busbars it is, but the short-circuit force calculation is what decides. Where the result approaches the rating, use a larger post or reduce the support span.
Can this be used outdoors?
Yes, with the creepage checked against the outdoor pollution class. 500 mm per unit is the figure to work from.
What mounting arrangement is supplied?
Metal end fittings are fitted to the porcelain core. Send your mounting drawing with the enquiry so we can confirm the fitting arrangement.
Does glaze colour affect performance?
No. Grey and brown are both available and the choice is cosmetic or specification driven.
What is the torsion rating used for?
800 N-m covers the reaction torque when a switch or disconnector mounted on the post is operated.
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Request A Quote for Station Post Insulators C4-125
Send the quantity, the destination port and the standard you buy against. Routine test records ship with the goods and type test reports are available on request.