Normally I'd guess this is incandescent since incandescent can run on a HPS ballast as long as you don't exceed the wattage (ie a 100W HPS ballast can run a 100W incandescent without modification to the wiring; the ignitor won't strike with an incandescent because it senses continuity, aka the lamp's "arc" is already struck).
250W and 400W HPS can run 250W and 400W MV lamps, respectively, with the ignitor bypassed/removed from the circuit. If you leave the ignitor connected, it will work fine as long as there is no hot restrike. If there is a hot restrike, the ignitor will fry the MV lamp. The lamp may still continue to light on the HPS ballast, but at that point, it can no longer work on the proper ballast since the ignitor fried the starting probe.
With 55V HPS (anything less than 150W and usually included 150W) MV will not work. Without the ignitor, nothing happens, since the HPS is only supplying half the required voltage. With the ignitor, it forces the lamp to ignite but it won't warm up. At this state, the lamp voltage is down, meaning the lamp current is way up, which is making the ballast run hotter.
This actually looks like an A shape MV lamp, since the etch is on the side and the lamp looks wider than a typical incandescent. If this is the case, the lamp won't warm up properly and it could kill the ballast if the ballast already runs hot. Maybe convince your mom to let you take a look at these at night? For the 250W MV on 250W HPS it will work fine (will kill the starting probe on the lamp, but it will not harm the fixture and the lamp will run at the proper specs).
Yep, must be. Wrong application for this lamp though! I'm sure they know nothing about HID specs anyway. I don't know a whole lot either, but I do know the basics, like MV only works on 250 and 400W HPS ballasts.
Normally I'd guess this is incandescent since incandescent can run on a HPS ballast as long as you don't exceed the wattage (ie a 100W HPS ballast can run a 100W incandescent without modification to the wiring; the ignitor won't strike with an incandescent because it senses continuity, aka the lamp's "arc" is already struck).
250W and 400W HPS can run 250W and 400W MV lamps, respectively, with the ignitor bypassed/removed from the circuit. If you leave the ignitor connected, it will work fine as long as there is no hot restrike. If there is a hot restrike, the ignitor will fry the MV lamp. The lamp may still continue to light on the HPS ballast, but at that point, it can no longer work on the proper ballast since the ignitor fried the starting probe.
With 55V HPS (anything less than 150W and usually included 150W) MV will not work. Without the ignitor, nothing happens, since the HPS is only supplying half the required voltage. With the ignitor, it forces the lamp to ignite but it won't warm up. At this state, the lamp voltage is down, meaning the lamp current is way up, which is making the ballast run hotter.
This actually looks like an A shape MV lamp, since the etch is on the side and the lamp looks wider than a typical incandescent. If this is the case, the lamp won't warm up properly and it could kill the ballast if the ballast already runs hot. Maybe convince your mom to let you take a look at these at night? For the 250W MV on 250W HPS it will work fine (will kill the starting probe on the lamp, but it will not harm the fixture and the lamp will run at the proper specs).