Specifications

ST900 Family General Handbook
667/HB/32900/000 Issue 12 Page 32 of 265
2.11.2 Lamp Drive Capability
The following table gives the lamp drive capability of the controller as a whole, each
‘Phase Driver’ (or ‘Lamp Switch’) card and each aspect. The ‘Watts’ and ‘Lamps’
columns are equivalents for the currents shown based on a 230V supply.
It must be noted that up to date information for Helios LED and Nearside units and
be found in the Helios General handbook 667/HB/30000/000.
Max
Current
(Amps)
Max
Power
(Watts)
Halogen
Maximum lamp current that a normal ST900
controller can supply excluding regulatory
signs and short-term illumination, i.e.
red/amber.
20A 4800W 76
Maximum lamp current that a ‘high-current’
ST900 can supply including short-term
illumination, i.e. red/amber, but excluding
Regulatory Signs. Also see note 1
30A 7200W 114
Maximum lamp current that an ST900LED
can supply including short-term illumination,
i.e. red/amber, but excluding Regulatory
Signs. Also see note 2
10A 2400W N/A
Maximum lamp load for one 8-Phase Driver
card (including red/amber). Also see note 2
20A 4800W 76
Maximum current for each four phase group
(e.g. phases A to D) for controllers not wired
for hardware fail flash. Also see note 3
10A 2400W 37
Maximum current for all green aspects on
one 8-Phase Driver card wired for hardware
fail flash. Also see note 3
10A 2400W 37
Maximum current for all red and amber
aspects on one 8-Phase Driver card wired
for hardware fail flash. Also see note 3
10A 2400W 37
Maximum load for one triac output on a
Phase Driver card. Also see note 4
4A 960W 15
Maximum supply for regulatory signs
(assuming 76 volt-amps per sign)
10A 2400W
30 Reg.
Signs
Maximum supply for LED regulatory signs
assuming Helios LED (LV) Also see note 5
10A 2400W
60 Reg.
Signs
Table 4 – ST900 Lamp Drive Capability
Note 1: The high-current ST900 uses the 30A Controller Kit. This increases the
current capability of the controller to 30A, excluding regulatory signs