AKA coring the door or drilling a raceway.
Like Moses leading the Hebrews across the Red Sea, you must work a miracle to bring electricity from the hinge side of the door to the lock side. Luckily it is a miracle on a much smaller scale. Moses had to deal with millions of gallons of water and miles of sea bottom whereas you only have to deal with a few feet of wood. So relax.
The best way to get a wire raceway into a door is to order the door with it already built in. This is especially true of hollow metal doors which often have cross members inside at angles to where the through-wire needs to go. However, that would require planning in advance – a rare occurrence these days, it seems. Lack of planning is the main reason that field-drilling a raceway becomes a necessity.
Coring the door is usually the best option whenever you are installing an electric lockset. This is true whether you use a door cord or an electric hinge. The safest place for the wire is inside the door.
You will probably also need to drill a raceway if you are using an electric strike in the inactive leaf of a pair of doors. Usually you will also need a door cord, electric hinge or other power transfer.
Horizontal vs. Vertical
It is possible to drill a raceway with the door still up. I have done it but I don’t recommend it. It takes nerves of steel and a stiff, sharp drill bit. You need a decent sized bit that won’t bend right or left on you as you try to drill straight, and you need to make sure that the door doesn’t move on its hinges while you are drilling.
I found that taking the door down and standing it on edge in a homemade door stand is the easiest for me because:
- The door is much less likely to move while you are drilling it
- Using a level to guide you is much easier, and
- Gravity is on your side
Certain constants apply to either horizontal or vertical drilling. In both cases I recommend a 3/8-inch by 3-foot drill bit. If the door is more than 3 feet wide, drill it from both sides or get a 4-foot bit. I prefer to drill from both sides because it’s a lot easier to drill straight for 18 or 24 inches than it is to drill straight for 3 or 4 feet.
If you have a drill with a built-in level, use it. If your drill does not have a built-in level, any level will do. Just put it against the door anytime you want to check the angle at which you are drilling. Determine if the door has a beveled edge and don’t let the bevel skew your path through the door. Make sure your drill bit remains parallel to both the interior and exterior surfaces of the door.
Drilling a raceway across a door is a challenge, but all it really takes is good focus and an ability to drill a straight hole. If you are challenged in the latter aspect, you might consider a drilling tool like the Security Door Controls product shown below. If you have many raceways to drill, a tool like this one is a great idea.