Specifications

ST900 Family General Handbook
667/HB/32900/000 Issue 12 Page 48 of 265
3.5 Mains Input
WARNING
When considering the connection of the controller to the incoming
mains supply, it is important to verify from the supplier that the mains
supply short-circuit current does NOT exceed 16,000 Amps.
If the mains supply short-circuit current can exceed 16,000 Amps, refer to Siemens
Poole for further information.
WARNING
The Master Controller Switch is a double-pole isolator and this must
be switched off before replacing the Master Controller Fuse.
3.5.1 Supply Transients
The ST900 ELV Controller has been designed to withstand transients as defined in
BS EN 50293:2001.
3.6 Lamp Supply Transformer
The ELV transformer has primary terminations that enable connection to the Mains
supplies shown below:
Nominal Voltage
Minimum Voltage* Maximum Voltage*
250V ** 213V 276V
240V 204V 276V
230V 196V 264V
220V 187V 253V
120V 102V 138V
110V 94V 126V
* Refer to the /HE/ handbook 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.