I just got my new 250w GE PSMH ballast. I am installing it in my m250r2, but, in the diagram, it shows one white common wire. However, there are 2 white wires that are stripped. Do I just connect both of these to common? Also ,there is a red wire coming from it. I assume that this connects to the red wire on the ignitor, but I don't know. CAn anyone help?

What is on the label? May you post it?
Some ballasts have the Neutral wire twice (internally connected together), to simplify the wiring towards other components (one for the mains input and second for the rest of the circuit), but that uses to be drawn on the label...

With the colors, unless it is explicitly stated in the manual and/or wiring diagram, I would not just trust the colors that much. The ballast and ignitor may come from different sources and each may use different colors...
So maybe the colors are matching, but then you would have to find some other "trace" speaking for that connection...
But on the other hand if you have (reliably) identified at least the Neutral wire(s) from the ignitor, there is not much danger from swapping the two others, the only consequence could be just the lamp not wanting to start so easily...

On the magnetic part of the ballast you see two distinct windings (they are physically separated by the magnetic shunt in the core). One, the primary, has a lead connected to the mains line input (either one, or in case of the multi tap ballast multiple). The secondary winding has it's start connected to the primary and it's end (that terminal has just one magnet wire to it) to the lamp. It then contains a tap for the ignitor connection, this tap has then two magnet wires going to it (well, I don't know if these details are visible on your ballast). Then the ignitor has one wire going to the lamp and one (usually labeled "pulse" or so) is connected to the tap on the ballast secondary and the 3'rd wire is the ground.

If you see the ignitor's internal components and those are one resistor (in the range of 3..22kOhm) in series with some small coil, one sidac (a small diode like component) and one capacitor (in the order of 100nF), the connection is as follows:
The wire going to the capacitor is connected to the lamp output.
The wire going to the DIDAC goes to the tap in the ballast
The series combination of the inductor and resistor are then going to the Neutral.

http://www.lighting-gallery.net/gallery/displayimage.php?album=lastup&cat=0&pos=0&pid=111554
Image of the label.

http://www.lighting-gallery.net/gallery/displayimage.php?album=lastup&cat=0&pos=0&pid=111554
Image of the label.

As the color coding is mentionned there for both the ballast and ignitor, it could be trusted.

The two white wires are depicted on the label, one goes from the transformer to the left side (to the mains), second to the right side to the lamp/ignitor... They are supposed to be used that way, as using just one would mean cramming too much wires into a single wire nut (mains + transformer + ignitor + lamp), with the depicted way you have no more than three wires on lamp side and two on the mains side (or three, if you want to install a halogen backup for a hot restrike delay).

Quote from: Zarlog on September 05, 2015, 01:26:42 AM

http://www.lighting-gallery.net/gallery/displayimage.php?album=lastup&cat=0&pos=0&pid=111554
Image of the label.

As the color coding is mentionned there for both the ballast and ignitor, it could be trusted.

The two white wires are depicted on the label, one goes from the transformer to the left side (to the mains), second to the right side to the lamp/ignitor... They are supposed to be used that way, as using just one would mean cramming too much wires into a single wire nut (mains + transformer + ignitor + lamp), with the depicted way you have no more than three wires on lamp side and two on the mains side (or three, if you want to install a halogen backup for a hot restrike delay).

Thank you. I got the ballast working properly and installed.

Would it be possible to simply leave the ignitor out altogether and use a standard M58 probe start lamp with this ballast ? Just curious...

There are two possible problems:

The first is with the ballast output current.
The M58 is rated for 2.1A, if I remember well the M153 is 3A, so that combination will overdrive the M58 (feed it by about 360W).
But with the M153 output being 3A I'm not 100% sure, so better to check with an A-meter... If the M153 output is 2.1A as well, the M58 may work, but.

Just to remind: The line input current is not relevant here, what matters is really only the secondary current to the lamp.

The second problem may be with the ballast OCV: Probe start MH's need the OCV of about 300V, while the pulse start usually suffice with just 200..250V range (same as MV's; the ignition spike is not included in that voltage figure). And the 200V would be too low to ignite and establish the main arc in the probe MH.

Assuming the lamp current is 2.1A like the M58, would it be suited to run a H37 250W mercury lamp instead ? (Essentially a mercury-only ballast)

Then yes, of course with disabled ignitor...
For MV's, the 200V is well sufficient OCV, problematic are only the probe start MH's.
But even there is no danger - the worst what may happen is the lamp would just not start...