I have some older mercury vapour bulbs, two flood bulbs and two regular (I forget the name of the common envelopes) that all still worked when removed. The flood bulbs are really well used and quite old. I think they’re from the 60s. I was wondering if I would be able to run them in some modern 400w metal halide fixtures without doing any damage to them. The fixtures had some cooked bulbs in them beforehand too.

The bulbs are all 400w mercury vapour and the etches are all still good if you want anymore information

Not sure what the gear set up is in Canada, but if you disconnect the ignitor you should be ok?
Mercury and halide gear is both the same in the UK ballast wise.

On probe start MH ballast yes, on pulse start MH ballasts not.

If you’re looking to run a H33 lamp on a ballast rated for M59, then yes. Otherwise, we would need more information as you would likely need to deactivate the igniter.

Probe start metal halide-ballasts (with no ignitor) sometimes had markings "for M59 or H33 lamps". PM me if you need such a ballast. I can give you one for free. Shipping from Montreal area.

Yeah a M59 (400w MH probe start) ballast with run 400w MV H33 without any modifications. The lamp type codes are usually printed on both the fixture nameplate and the ballast nameplate.

As mentioned above, the older M59 ballasts were often marked with H33 too, it was taken off after 2008 to comply with US regulations but are basically the same ballast as the old ones with both types.

M155/M135 ballasts (400w MH pulse start) will run the 400w MV lamps with a minor modification. You have to either remove or disable the ignitor. Most ignitors used here have three wires marked X1, X2, X3.

The bulbs are all h33, when I get back to the place with the halides I’ll relay all the information on the labels. I believe the old halide bulbs are probe start.