Lamp Supply Transformer; Hpu - Siemens ST950 Handbook

4.6

Lamp Supply Transformer

The 48V ELV transformer has primary terminations that enable connection to the Mains
supplies shown below:
Nominal Voltage
250V **
240V
230V
220V
120V
110V
* Refer to the ST950ELV Installation and Commissioning Handbook 667/HE/45950/000
for the recommended input tap for a specific mains voltage.
** Available from issue 4 onwards of the Lamp Supply Transformer
The nominal secondary voltages are as follows:
48V Bright Lamp supply, 27.5V Dim Lamp supply
24V Detector supply
48V Regulatory Sign supply
Logic supplies for LSLS cards (one supply per LSLS card)
The transformer has an earthed screen to reject common mode disturbances on the
Mains supply.
For the 40/42V ELV Controller, see section 4.12
4.6.1 Low Inrush Lamp Supply Transformer Option
A low inrush lamp supply transformer option (factory fit only*) is available for the ST950
ELV controller that allows the controller to be run from a 25A Electricity Board cutout
which many suppliers will provide without metering.
The transformer is both larger and heavier so a second transformer cannot be mounted
in the cabinet. This means that only a 20A controller is available.
* - No upgrade option is available because of the size and weight of the transformer.
4.7

HPU

4.7.1 Introduction
The High Power Unit (HPU) is mounted on the left hand side panel of the controller,
above the lamp supply transformer.
The HPU (High Power Unit) receives all the AC voltages from the transformer
secondary windings and develops rectified, unsmoothed DC supplies for the LSLS
Security classification
Version
Last Editor
Document Name
Copyright © Siemens plc 2015. All Rights Reserved.
Minimum Voltage*
213V
204V
196V
187V
102V
94V
Table 7 – ST950 ELV 48V Lamp Supply Transformer
Unrestricted
4
Paul Cox
ST950 General Handbook
Mobility Division, Traffic Solutions
Sopers Lane, Poole, Dorset, BH17 7ER
Maximum Voltage*
276V
276V
264V
253V
138V
126V
Page 42 of 107
Status Issued
Date 16-Jul-2015
Document No. 667/HB/46000/000
Mobility is a division of Siemens Plc