Electrical 101

Tombstone Lampholders

Bipin and tall bipin

To remove the bulb, gently rotate 1/4 turn in either direction.
Insert the tube pins on the same side of each of the lampholders. Make sure the bulb is all the way into the lampholders and gently rotate 1/4 turn. As the tube is rotating, insert the pins into the other side of the lampholders. (Use alignment marks to indicate the tube is set properly).

Tube alignment mark

Bipin U-shaped

To remove the bulb, gently lift the tube straight out.
Insert all four tube pins on top of the lampholders. Gently push the tube into the lampholders. These lampholders have tension that will hold the tube in place after the tub is inserted (no rotating of the tube is needed).

Type HO Tombstone

One of the two lampholders is spring loaded.

To remove the bulb, push the tube toward the spring loaded lampholder and remove the tube at the other lampholder. Then remove the lamp from the spring loaded end.
To install, insert a tube end into the spring loaded lampholder and push in. This will allow the other end of the tube to be inserted into the other holder.

Tombstone Lampholder Wiring

Swap Terminals on Non-Shunted Lampholders

Tombstone non-shunted bipin

Bypin U-shaped

HO/VHO single pin plunger end

HO/VHO single pin fixed end

Bypin

Tall Bypin

Tombstone shunted bipin

How to Replace Fluorescent Tubes

A fluorescent tube should always be replaced with the same diameter bulb. The lampholders are made of plastic, so be careful not to break them when replacing these bulbs. Turn off the light switch before replacing bulbs. If you have difficulty gripping the bulb, use rubber gloves.

Tombstone bipin

To remove the bulb, gently rotate 1/4 turn in either direction. If they don’t turn easily, reverse the direction of rotation to see if it turns more easily. Increase pressure while rotating the bulb until it is removed.
Insert a new bulb into the lampholders. Make sure the bulb is all the way into the lampholders and gently rotate 1/4 turn in either direction (bulbs usually have alignment marks to indicate proper rotation).