---
title: "HST - Power collection - Safety sequence"
canonical: "/hst-power-collection-safety-sequence"
published: 2026-10-12
---

# HST - Power collection - Safety sequence

## Frame

## Frame

**Rail**

**HST**

**Power collection**

**Pantographs and strips**

**GRU**

**Roof disconnectors**

**switches**

**safety sequence**

## Frame

### Safety sequence 22RUM4 & key multiplier

##### Safety sequence 22RUM4 &key multiplier

##### For safety reasons, before opening the doors of the traction boxes, a safety sequence must be completed to ensure current is earthed. The sequence starts on the driver's desk or with the pneumatic valve and goes through multiple keys to allow time to discharge the capacitors via resistors. This ensures maintenance workers are safe from current.

###### POWER COLLECTION

##### Safety sequence 22RUM4 & key multiplier

**Customer benefits**

**Safety sequence 22RUM4 & key multiplier**

## Frame