---
title: "HST - Power collection - Roof disconnectors"
canonical: "/hst-power-collection-roof-disconnectors"
published: 2026-10-12
---

# HST - Power collection - Roof disconnectors

## Frame

## Frame

**Rail**

**HST**

**Power collection**

**Pantographs and strips**

**GRU**

**Roof disconnectors**

**switches**

**safety sequence**

## Frame

### PPAD77

##### Outside Roof disconnector OSAD44

##### Roof disconnectors are needed to connect the pantograph to the circuit, as well as earthing current in the case of low voltage. In case of a short circuit, the roof disconnector will disconnect the pantograph from the line to make sure the circuit is earthed.

##### Our innovative line of roof disconnectors is unique in its vertical design, allowing it to take as little space as possible around the pantograph on the roof. OSAD44 is meant to be mounted outside of the vehicle.

###### POWER COLLECTION

##### Roof Disconnector OSAD44

**Customer benefits**

### Roof disconnector OSAD27

###### POWER COLLECTION

##### Roof Disconnector OSAD27

##### Roof disconnector OSAD27

##### This roof disconnector is suitable for applications where earthing is not needed and only disconnection is required. It is used to disconnect the pantograph or to disconnect the roof line. This is a horizontal switch.

**Customer benefits**

### Roof disconnector OSAD44

##### Inside Roof disconnector PPAD77

##### Roof disconnectors are needed to connect the pantograph to the circuit, as well as earthing current in the case of low voltage. In case of a short circuit, the roof disconnector will disconnect the pantograph from the line to make sure the circuit is earthed.

##### Our innovative line of roof disconnectors is unique in its vertical design, allowing it to take as little space as possible around the pantograph on the roof. PPAD77 is meant to be mounted inside the vehicle.

###### POWER COLLECTION

##### Roof disconnector
PPAD77

**Customer benefits**

**OSAD44**

**OSAD27**

**PPAD77**

## Frame