Engineering Change Release Note

Siemens Traffic Controls

Technical Action Bulletin

Siemens Technical Action Bulletin No. /

STAB03-0002

ISSUE 2
TITLE / HELIOS L.E.D. Signal Heads

Product

ST800/

ST700 /

T400

Cuckoos

OMU

Street Furniture

/ MOVA / OTU / INSTATION SOFTWARE / OTHER
/ / / / /

▲

/ / / /

Are Modifications Required ?

Yes

Retrospective Action Required ?

No

Priority of the Change

URGENT ASAP

ACTION AT NEXT SITE VISIT

ACTION WITHIN 3 MONTHS

ACTION AT NEXT PI

ACTION ONLY IF PROBLEM ARISES

/ INFORMATION ONLY
/ / / / /

▲

Introduction

/ Some Helios L.E.D. Signal Aspects are occasionally blowing their PCB fuse (2A).
Investigations at Poole of returned PCBs and PSUs have highlighted 2 main problems –
1) Some PCBs have an 2 off incorrect wattage resistor fitted to the Heastsink
2) A problem has been identified with some PSUs

Scope

/ All Helios L.E.D. Signal Heads

Procedure

/ If an LED Aspect blows its PCB fuse, replace the PCB and PSU with the following –
1) A L.E.D. PCB that has had the correct wattage load resistors fitted (the 2 that are mounted on the Heatsink).
These load resistors should be of the 50 watt type.
(Correct type of resistor marked – RTO 50 F 470Ω 5%)
(Incorrect type of resistor marked – MPR-20 471CJ)
2) A modified PSU. This is identified by a Red spot on the PSU cover and a Red spot on the PSU itself.
Return the faulty PCB and PSU to Poole for upgrade and testing.
NOTE – If a single aspect in a signal head fails it is suggested that the remaining aspects in that signal head are replaced with updated PCBs and PSUs.
NOTE – If over a short period (1 – 4 Weeks) 2 or more aspects fail at a junction, it is recommended that all aspects are upgraded.
NOTE - If it can be identified that PCBs have the correct resistor fitted, identified above, then only upgrade the PSUs.
(Ensure that the PCB is fitted with a Slow Blow 2A 250v 20 x 5mm High Breaking Capacity fuse (518/4/90302/010)).
It should be noted in a separate log in the controller as to what upgrade work has been carried out to which aspects. This should help to identify any aspect that continues to fail and allow any part that has not already been changed to be upgraded.