What sodium bulb replacement

[yottie]

Over the years, as the unit has failed, I have bought a new o/s sodium fitting for security. The unit is fairly high up and, not knowing which part had failed, it was easier to replace (£25) than sort out up there !
Consequently I have amassed a few duff units which I would like to re-activate. Am having trouble finding replacement bulbs (which I thought I would start with), these are es screw..Sylvania SHP 70w/CO-1, along with other makes.
Can any-one tell me if the bulb is the likely culprit and, if not, is it worthwhile replaceing the other "bits", and where can I get the "bits" please

 

[Spark123]

Are the lamps integral ignitors or external ignitors, usually denoted by a I or an E in a triangle on the lamp? You need to use the correct lamp for the type of fitting.
It isn't possible to say what the most likely part to fail is, if a lamp has died and has been left in the fitting long enough it could make the ignitor or the ballast also fail.
The easiest thing to do would be to replace the lamp first and if that doesn't work, look further.

 

[333rocky333]

If the lamps are internally ignited , all that usually goes wrong is the lamp and sometimes the 70 watt 1.0 amp ballast within the fitting.
Look in the fitting all it will have is the sguare ballast, and maybe a 12uf capacitor
You can usually see if the ballast is burnt out.
So maybe worth trying a lamp

If the lamps are exterrnally ignited, the fitting is the same as above but will also have an igniter inside.
This time the fault could be the lamp, ballast ,or igniter.

You can test the ballast on both types, by checking continuity or by safely checking the voltage into it and the voltage out
both should be about 230 volt when tested to neutral.

Do not test the igniter OUTPUT if you have one ,when the power is on, this is in excess of 1000 volt and may damage your tester.
The igniter will usually buzz if it is working, for approx 20 secswhen powered up.

If the igniter is duff it may be cheaper to remove it. alter the internal wiring and fit an internally ignited lamp.

Ext ignited lamp has an E inside a triangle ,stamped on the glass
Int ignited lamp has an I inside a triangle , stamped on the glass
You need to see if you have an igniter in the fitting, and if it works still, to work out what lamps you want.
Then search for a 70 watt SON-E for an oval shape lamp ,or a 70 watt SON-T for a tubular shape lamp
Both types are made internal ignited (igniter inside the lamp)
and external ignited (igniter inside fitting)

Igniters can be over £10
Ballasts can be over £10
www.bernlite.co.uk
TheCapacitors rarely go wrong, unless damaged somehow
Lamps could be over £5
The £25 fittings usually have no igniter in the fitting, and an internally ignited lamp, which is why they are so cheap.