Earthing Equipment

Earthing (grounding) equipment keeps a line or installation that has been disconnected and verified dead safe throughout maintenance. In unexpected situations such as an incorrect switching operation, back-feed or induction from nearby lines, it holds the work location at earth potential. Distribution and transmission system operators, industrial companies with medium-voltage consumer installations, substation operators and maintenance contractors are the main users of this equipment.

How to choose the right model

• Place of use: Cubicle-type sets (Type H, Type HA-W, Type HC, Type HF) are used for switchgear cubicles and high-voltage consumer installations, and telescopic earthing rods (Type Z, ZB, Y, YB) for power transmission lines. For railway applications, see the earthing hooks on the railway products page.
• Stick locking method: Transmission line rods come in two designs: compression-locking telescopic (Type Z / ZB) and push-button telescopic (Type Y / YB). The handling your crew is used to and the length required decide the choice.
• Disconnector operation: Opening and closing disconnectors is done with separate rods. The HSH-K6 with built-in voltage detector is used at AC 6.6 kV, the SA109 series at AC 10 – 110 kV, and the D Series inside cubicles at AC 6.6 – 30 kV.
• Residual charge: In capacitive loads such as cables and capacitors, a charge can remain after disconnection. Discharge sticks are used to release it; the HRD-27S signals completion of the discharge with an audible and visual indicator.
• Non-standard requirements: For custom-made sets, the tip fitting, stick type (jointed or telescopic), stick length and diameter, cable cross-section and length, earthing clamp and operating voltage are specified when ordering.

Subcategory	Models	Operating voltage
Cubicle Earthing Sets	Type H, Type HA-W, Type HC, Type HF	Confirmed against the installation voltage
Transmission Line Earthing Sets	Type Z, Type ZB, Type Y, Type YB	Confirmed against the line voltage
Disconnector Operating Rods	HSH-K6, SA109, D Series	AC 6.6 kV / AC 10 kV – 110 kV / AC 6.6 kV – 30 kV
Discharge Sticks	HRD-27, HRD-27S, simple discharge stick	Discharge voltage up to DC 27 kV (HRD-27 / 27S); AC 6.6 kV (simple type)
Custom Earthing Equipment	Fixed / detachable set	Specified when ordering

Safe use

• Before earthing, verify the absence of voltage at the work location with a suitable voltage detector.
• When connecting, attach the earth end first and then the line end; reverse this order when removing.
• On capacitive loads, release the residual charge with a discharge stick before earthing.
• Do not work with damaged cables, loose clamps or cracked sticks; inspect the equipment visually before every use.

For the basic rules, see our article Earthing Sets: Key Rules for Safe Work on Power Lines; for residual charge, see What Is a Discharge Stick?.

Frequently Asked Questions

Do an earthing set and a discharge stick do the same job?

No. A discharge stick is used briefly to release residual charge; an earthing set stays connected throughout maintenance to protect the work location. On capacitive loads the two are used one after the other.

What information should I prepare for a custom-made set?

The operating voltage, the design of the conductor and earthing point to be connected, the required stick length and the cable cross-section and length are a sufficient starting point. The standard set is supplied for AC use as 3 phases / 1 set.