Kevin C
Well-known member
Standard Ballast Factor to High Ballast Factor Upgrade.
Last week I bought a T8 4 bulb fixture for my shop to go between the garage doors. The idea was to replace the two bulb fixture to get a little bit more light at that end of the shop.
http://www.homedepot.com/p/Lithonia-Lighting-4-Light-Grey-Heavy-Duty-Shoplight-1284GRD-RE/202968125#.UpvXJdLrycU
The original two bulb fixture had a ballast factor of 1.2 and put out a decent amount of light, but I wanted more.
The new one looked promising. Once I got it home I realized that it was not much of an improvement. Four bulbs and a ballast factor of .8 did not provide a whole lot more light.
Assuming 2900 lumens at a Ballast factor of 1 my original light put out:
2 x 2900 x 1.2 = 6960 raw lumens.
The new fixture:
4 x 2900 x .8 = 9280 lumens. This is a normal factor ballast, but its to the low side of the spec.
Not the 2x improvement I wanted.
I picked up a Phillips Commercial ballast PN IOPA-4P32-HL . This model number has a ballast factor of 1.18 when used with four bulbs.
4 x 2900 x 1.18 = 13688 raw lumens. That's more of what I had in mind!
Very easy swap. I used a pick to remove the leads from the sockets and crimps on the line voltage. To minimize EMI I made a point of maximizing the spacing the line voltage conductors from line to the lamps.
I also eliminated the internal auxiliary socket since its wires run the full length of the fixture ( great opportunity for cross talk).
The fixture is not Class B consumer rated, this is a class A commercial fixture with power factor correction.
30 minutes of work and $25 for a significant (48%) improvement in light output (same fixture with new ballast) or about 100% improvement compared to the original fixture.
My new favorite spot for reading instructions.
Last week I bought a T8 4 bulb fixture for my shop to go between the garage doors. The idea was to replace the two bulb fixture to get a little bit more light at that end of the shop.
http://www.homedepot.com/p/Lithonia-Lighting-4-Light-Grey-Heavy-Duty-Shoplight-1284GRD-RE/202968125#.UpvXJdLrycU
The original two bulb fixture had a ballast factor of 1.2 and put out a decent amount of light, but I wanted more.
The new one looked promising. Once I got it home I realized that it was not much of an improvement. Four bulbs and a ballast factor of .8 did not provide a whole lot more light.
Assuming 2900 lumens at a Ballast factor of 1 my original light put out:
2 x 2900 x 1.2 = 6960 raw lumens.
The new fixture:
4 x 2900 x .8 = 9280 lumens. This is a normal factor ballast, but its to the low side of the spec.
Not the 2x improvement I wanted.
I picked up a Phillips Commercial ballast PN IOPA-4P32-HL . This model number has a ballast factor of 1.18 when used with four bulbs.
4 x 2900 x 1.18 = 13688 raw lumens. That's more of what I had in mind!
Very easy swap. I used a pick to remove the leads from the sockets and crimps on the line voltage. To minimize EMI I made a point of maximizing the spacing the line voltage conductors from line to the lamps.
I also eliminated the internal auxiliary socket since its wires run the full length of the fixture ( great opportunity for cross talk).
The fixture is not Class B consumer rated, this is a class A commercial fixture with power factor correction.
30 minutes of work and $25 for a significant (48%) improvement in light output (same fixture with new ballast) or about 100% improvement compared to the original fixture.
My new favorite spot for reading instructions.
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