# Pulse start bulbs



## MHElectric (Oct 14, 2011)

When I got into Lighting I was amazed at how many different style lamps there actually were. Everytime we would service a new chain, we would run into different style bases, ballsts and lamps than we had on stock. And we all kept at least 15-20 different types of flourescent & MH lamps/ballasts on the truck. 

Sucks buddy. I feel your pain.


----------



## HertzHound (Jan 22, 2019)

I thought all pulse start lamps have a rejection tab on the lamp base so they can only screw in so far. So they won’t make a connection on a standard base? I didn’t know there was a difference between open or enclosed. Since it’s a different ballast between the two, what would stop interchangeability?

Is it possible it has had the wrong lamps in the past? That would explain the short life. 









Pulse start lamp with standard ballast?


Are there any issues with installing a 400w MH (m155) pulse start lamp in a standard 400 metal halide (m59) fixture?




www.electriciantalk.com


----------



## VELOCI3 (Aug 15, 2019)

HertzHound said:


> I thought all pulse start lamps have a rejection tab on the lamp base so they can only screw in so far. So they won’t make a connection on a standard base? I didn’t know there was a difference between open or enclosed. Since it’s a different ballast between the two, what would stop interchangeability?
> 
> Is it possible it has had the wrong lamps in the past? That would explain the short life.
> 
> ...


I changed them in the past. I think the supply house just carries the exclusion base in pulse and non pulse just to be safe with limited inventory space. You can use the open rated in either in enclosed fixtures but not the opposite. Some rule change in the NEC 2005 edition regarding lamp safety


Sent from my iPhone using Tapatalk


----------



## kb1jb1 (Nov 11, 2017)

I thought the different bases were for vertical only and universal burn position.


----------



## VELOCI3 (Aug 15, 2019)

kb1jb1 said:


> I thought the different bases were for vertical only and universal burn position.


That’s for the lamps not the sockets


Sent from my iPhone using Tapatalk


----------



## VELOCI3 (Aug 15, 2019)

I nipped off the raised part of the shell so the lamp can make contact with the terminal. Nobody around me has sockets and because the lamps are 350 watt nobody has stock either. Hopefully this hack approach will do the trick.










Sent from my iPhone using Tapatalk


----------



## VELOCI3 (Aug 15, 2019)

Well the hack worked. Nice part is the socket pins have a spring under the center voltage tab. 


Sent from my iPhone using Tapatalk


----------



## MotoGP1199 (Aug 11, 2014)

HertzHound said:


> I thought all pulse start lamps have a rejection tab on the lamp base so they can only screw in so far. So they won’t make a connection on a standard base? I didn’t know there was a difference between open or enclosed. Since it’s a different ballast between the two, what would stop interchangeability?
> 
> Is it possible it has had the wrong lamps in the past? That would explain the short life.
> 
> ...





kb1jb1 said:


> I thought the different bases were for vertical only and universal burn position.


The difference in base is for enclosed fixtures and open fixtures. The main reason is for safety. The bulbs designed for open fixtures have a protected arc tube(hardened case). The standard lamps which are unprotected can explode when they reach the end of their life. The protected lamps designed for use in open light fixtures will contain the broken arc tube if it fails. This is why they are allowed to be used in either situation, they just cost a little more. If the lamp is used in the wrong position you mostly just lower the life and they operate less efficiently, and if it is the unprotected arc style it can explode when it fails.


----------

