A closet light controller switches a closet light from a magnetic door switch: the light turns on when the door opens and turns off when it closes. Functional Devices, Inc. manufactures the CLC Series of closet light controllers, which take the door switch on a Class 2 input and need no stepdown transformer. The CLC106 is the retrofit model for 120 Vac lighting circuits. The CLC212 series covers new construction at 120–277 Vac, including the CLC212-D15 and CLC212-D60, which turn the light off after 15 or 60 minutes if the door is left open.
Using a general-purpose relay such as the RIBU1C to control a closet light potentially requires a stepdown transformer. The door switch sits in a low-voltage control circuit, and that circuit needs a source, so the installation adds a transformer and its wiring to what would otherwise be a relay and a switch.
The CLC Series removes the transformer from that circuit. The controller is powered from the lighting circuit it switches, and the door switch connects to a Class 2 input on the controller, so the switch only opens and closes a circuit that the controller already provides. On the CLC212 models, control wiring to the door can be light 18 AWG wire rather than armored cable.
Closet Light Controller Models by Application
Functional Devices offers six CLC Series models, grouped by installation type. The retrofit and new construction models differ in supply voltage, contact rating, mounting, and whether a door switch is included.
- For retrofit work on 120 Vac lighting, the CLC106 uses a 5 A single-pole, single-throw, normally open (SPST-N/O) relay rated for resistive, electronic ballast, magnetic ballast, and tungsten loads. It mounts inside the existing fixture junction box with a retaining clip for a 1/2” knockout and ships with a magnetic door switch on 6-foot leads.
- For new construction, the CLC212 runs on 120–277 Vac with a 10 A SPST-N/O relay (10 A general use at 277 Vac) and a separated Class 2 dry contact input. It mounts through a 1/2” knockout on a 0.50” NPT hub. The door switch is sold separately.
- For closets where the door is often left open, the CLC212-D15 adds a 15-minute delay, and the CLC212-D60 adds a 60-minute delay. Both share the CLC212’s ratings, supply voltage, and mounting, and use a separately purchased door switch.
- For the opposite operation, the CLC106-NC and CLC212-NC replace the N/O relay contact with a normally closed (N/C) contact. On the CLC106-NC, the light is on when the magnetic switch is closed and off when it is open, the reverse of the CLC106.
Commercial lighting circuits are commonly 277 Vac, which the CLC106 does not accept and the CLC212 models do. The CLC106, CLC212, CLC212-D15, and CLC212-D60 carry a 10-year warranty.
How Time-Delay Closet Light Controllers Work
The CLC212-D15 and CLC212-D60 turn the light on when the door opens and start a timing sequence at the same time. If the door is closed before the delay runs out, the light turns off and the timing sequence ends. If the door is left open, the light turns off when the delay expires: after 15 minutes on the CLC212-D15 and after 60 minutes on the CLC212-D60.
To keep the light on indefinitely with the door open, the door should be opened, closed, and reopened within three seconds. On the standard CLC212, the light stays on for as long as the door stays open. The delay is built into the controller, so no separate time delay relay is added to the circuit.
Door Switches for Closet Light Controllers
Functional Devices offers two magnetic door switches for the CLC212 models: the ACLCMAGSM for surface mounting and the ACLCMAGDJ for recessed mounting. Both are Form C switches, with an N/O contact and an N/C contact on a shared common (COM). Which contact is used depends on how the controller reads its input:
- CLC212: The controller activates when its input closes, so the door switch’s N/C contact is used. With the magnet in place (door closed), the N/C contact is held open; when the door opens, the contact closes and the light turns on.
- CLC212-D15 and CLC212-D60: The controller activates when its input opens, so the N/O contact is used. With the door closed, the N/O contact is held closed; when the door opens, the contact opens and the light turns on.
The CLC212-NC opens its relay contact when its input closes, the reverse of the CLC212, so it is wired to the door switch’s N/O contact for a light that turns on when the door opens.
The CLC106 and CLC106-NC ship with their own magnetic door switch and need no separate switch.
A common installation problem is a light that operates in reverse (turning on when the door closes and off when the door opens). Magnetic door switches are frequently sourced from security suppliers, and a switch selected for a security application can have the opposite contact from what the controller expects. With a Form C switch, reversed operation is corrected at the switch by moving the control wire to the other contact, and no replacement switch is needed. Where a CLC212 is paired with a single-contact switch that can’t be changed, the CLC212-NC reverses the operation at the controller.
Wiring Closet Light Controllers for Dual-Door Closets
A closet with two doors uses one door switch per door. The switches—or, for the CLC106, the controllers—are wired in series or in parallel. Because the CLC212 and the timed models read the switch in opposite states, the same arrangement produces opposite results:
- CLC106 and CLC212: Parallel wiring turns the light on when any door opens and off only when all doors are closed. Series wiring turns the light on only when all doors are open.
- CLC212-D15 and CLC212-D60: Series wiring turns the light on and starts the timing sequence when any door opens, and turns it off when all doors are closed. Parallel wiring turns the light on only when all doors are open.
The difference is due to the input. On the CLC212, an open door closes its switch contact, so switches in parallel let any one door complete the input circuit. The timed models activate when the input opens, so switches in series let any one door break it. The CLC212 models take both door switches on a single controller. A dual-door CLC106 installation uses two controllers, one per door, each with its included switch, and the series or parallel connection is made between their switched outputs. Wiring diagrams for each arrangement can be found in the Closet Light Controller Selection Guide.
Frequently Asked Questions About Closet Light Controllers
Can I use an RIBU1C to control a closet light?
Yes, but the installation requires a stepdown transformer to supply the low-voltage circuit that runs through the door switch. The CLC Series removes the need for a transformer altogether because the door switch connects to a Class 2 input on the controller. A CLC Series controller is the right device when the only control input is a door switch.
Does a closet light controller need a transformer?
No. CLC Series controllers are powered from the lighting circuit they switch: 120 Vac for the CLC106 models and 120–277 Vac for the CLC212 models. The door switch wires to a Class 2 input on the controller, so no separate control voltage is needed.
Why does my closet light turn on when the door closes?
The door switch is wired to the wrong contact for the controller. The CLC212 uses the door switch’s N/C contact, and the CLC212-D15 and CLC212-D60 use the N/O contact. On a Form C switch such as the ACLCMAGSM or ACLCMAGDJ, moving the control wire to the other contact corrects the operation. If the switch has only one contact, the CLC212-NC reverses the operation at the controller.
What is the difference between the CLC106 and the CLC212?
The CLC106 is the retrofit model: it runs on 120 Vac, carries a 5 A relay, fits inside the fixture junction box, and includes a magnetic door switch. The CLC212 is the new construction model: it runs on 120–277 Vac, carries a 10 A relay, mounts on a 0.50” NPT hub, and is used with a separately purchased door switch. Both are available in -NC versions with a normally closed relay contact, and time-delay versions are available only in the CLC212 series.
Can one closet light controller handle a closet with two doors?
Yes, for the CLC212 models: one controller is wired to two door switches, in series or in parallel. To turn the light on when either door opens, the switches are wired in parallel on the CLC212 and in series on the CLC212-D15 and CLC212-D60. Dual-door installations with the CLC106 use two controllers.
Find a Closet Light Controller Distributor
To specify a closet light controller, browse our CLC Series closet light controllers or find an authorized Functional Devices distributor near you.