Fault on three phase sports floodlighting

[spud1]

Hi,

I have a single fitting on a 3 gang, 3 phase floodlight over an astro-turf at a school that wont work. I have changed the 2kW MH lamp with no joy. Is there a safe way I can test the dedicated ballast and ignitor for correct operation? There is voltage on the incoming terminals on the ballast but don't want to test the outgoing side until I get some advise about what I might be looking for, for fear of frying my meter and myself!

Thanks in advance.

 

[Leesparkykent]

Have You checked for fuses on the gear tray?

 

[spud1]

Have You checked for fuses on the gear tray?

Yeah there are some front end double pole D curve MCBs wired before the ballast they are all on and letting through. Just wanna avoid buying a new ballast if its the ignitor at fault and vice versa.
I know from fluorescent circuits that a ballast can still have outgoing voltage and not be doing its job properly so didn't know whether there was another test I could be doing to prove or disprove integrity and correct operation of the ballast and ignitor respectively?

 

[Leesparkykent]

Have you Check for voltage at the lamp holder?

you might have to disable the igniter

 

[VoltzElectrical]

Buy a new ignitor and ballast, change the ignitor. If the lights work you have fixed the problem, and you can take the ballast back. If not, change the ballast. Now if the lights work, you have still fixed the problem.

I must change a dozen ballasts a week in my day job.

 

[spud1]

Buy a new ignitor and ballast, change the ignitor. If the lights work you have fixed the problem, and you can take the ballast back. If not, change the ballast. Now if the lights work, you have still fixed the problem.

I must change a dozen ballasts a week in my day job.

Good point. Whats the betting that ballast/ignitor are specials and incur a return carriage charge. Prob the best way though you are right, would have been interesting to learn of any tests I could perform as an alternative though. Maybe there aren't any.

 

[Plonker 3]

Is there not another light the same on site you can swap the parts out from to find whats faulty?

 

[Brightspark2]

It will more than likely be the ignitor...if it's the ballast that's gone then it usually operates the protective device...

The way forward is as Dillb says, swap the parts with a working fitting...starting with the ignitor...

 

[Deleted member 9648]

If there is full voltage on the output side of the ballast it will likely be ok....As above,chances are it'll be the ignitor. Dont discount the obvious though,are you certain the lamp is good?test it in a working fitting.

 

[Charlie_]

Firstly carry out a visual inspection; obvious stuff like terminations, signs of over heating to components, blown capacitor and signs of damage to ignitor.
The sniff test is also useful, if you know what you're sniffing for

if if you have a healthy ignitor handy try it.

Tests;
dead..
Capacitor(dead test)
Continuity of windings
Some ballasts have thermal protection
live..
Input voltage to ballast
Carry out an open circuit voltage test at the lamp terminals.
With lamp in situ take some current readings at the input and output(lamp end)
If you have a HV probe or meter you can check the ignitor.. Don't try it with a standard meter as the pulse will be upto 5Kv.

what are the symptoms? Is the lamp arcing on start up?

 

[spud1]

Firstly carry out a visual inspection; obvious stuff like terminations, signs of over heating to components, blown capacitor and signs of damage to ignitor.
The sniff test is also useful, if you know what you're sniffing for

if if you have a healthy ignitor handy try it.

Tests;
dead..
Capacitor(dead test)
Continuity of windings
Some ballasts have thermal protection
live..
Input voltage to ballast
Carry out an open circuit voltage test at the lamp terminals.
With lamp in situ take some current readings at the input and output(lamp end)
If you have a HV probe or meter you can check the ignitor.. Don't try it with a standard meter as the pulse will be upto 5Kv.

what are the symptoms? Is the lamp arcing on start up?

The lamp is showing no signs of life on start up no.
What dead test can I carry out on the capacitor?
Also when you say an open circuit voltage test at the lamp terminals I take it you mean across the lamp holder with the lamp removed?
Will my standard 10A max multimeter be man enough to take current readings at the output and input of the ballast as you suggest for the 2kW lamp? I know a 2kW load translates as roughly 8.7 amps single phase but not sure if the calculation is different because its 3 phase?
And I don't have an HV probe or meter.

 

[spud1]

Is there not another light the same on site you can swap the parts out from to find whats faulty?

Yes there is good point. Thanks.

 

[Leesparkykent]

The lamp is showing no signs of life on start up no.
What dead test can I carry out on the capacitor?
Also when you say an open circuit voltage test at the lamp terminals I take it you mean across the lamp holder with the lamp removed?
Will my standard 10A max multimeter be man enough to take current readings at the output and input of the ballast as you suggest for the 2kW lamp? I know a 2kW load translates as roughly 8.7 amps single phase but not sure if the calculation is different because its 3 phase?
And I don't have an HV probe or meter.

if you do this disconnect the ignitor.

 

[spud1]

if you do this disconnect the ignitor.

OK yes because of the pulse?

 

[Leesparkykent]

OK yes because of the pulse?

Yes as your DMM might not handle it.