Everbrite MedLux™ Support Site
Spec & Installation Info Site


Q: What is the difference between MRI and non-MRI Ceiling GPI?
When a Ceiling GPI is mounted in an MRI room, the power source must be outside of the MRI room.
Normally this means that the 48VDC 600W power supply is mounted in the equipment room.
The power enters the MRI room with a facility filter, and there is a fuse and distribution box mounted to it.
The dimming control unit is normally mounted in the control room and enters the MRI room with a signal filter.
The output of the signal filter is wired into the fuse and distribution box and special cables connect the GPIs together.

However, when a Ceiling GPI is not in a MRI room, then we can make a self-powered master GPI that powers other GPIs.
The number of satellite Ceiling GPI fed from one 48VDC 90W master unit varies depending on the size of the GPIs.
No filters are required, and the dimming signal comes directly from the dimming control unit on a CAT-5 cable.

Q: How does the Ceiling GPI work?
The purpose of a Ceiling GPI is to provide an appealing, evenly lit graphic to soothe the patient.
The Ceiling GPI should not be used as a primary light source as the brightness is reduced to make the graphic faceplate look good.
The GPI are powered by 48VDC from the ELT600-48U power box. and are fully on without a dimming control connected.
The dimming control can be our ECL-53-CR, or a commercial 0-10V control in conjunction with our XLIM box.
These GPI fixtures cannot be dimmed by incandescent lighting dimmers or fan speed controls.
Both the 48VDC and the dimming control signal must be filtered before entering the MRI shielded room.
The ECL-53-CR dimmer may be used in the MRI shield room due to its special waveform and shielding, but the XLIM box cannot.
However, locating the ECL-53-CR it in the shield room may not be possible with some newer highly sensitive open-bore magnets.

When the Ceiling GPI is not in an MRI room, no filters are required, and the dimming signal comes directly from the dimming control unit.
The ECL-53-CR or the XLIM are normally powered by a 16VAC 10VA "doorbell transformer" with a 120VAC primary voltage.
A 24VAC 20VA transformer can also be specified to power the ECL-53-CR or XLIM with a 277VAC primary voltage.
Either of these AC transformers mount to a double width electrical outlet box with the provided cover plate.
Q: What are the wiring rules for installing a Ceiling GPI?
The 48VDC output of the facility filter enters a fuse and distribution box in order to assure UL Class II compliance.
Each fused output (run) from the fuse and distribution box can power 6 of the 2x2, 3 of the 2x4, or 1 of the 4x4 troffers.
When using a signal filter to broach the MRI room wall, you must solder the wires on the equipment room input side of the filter!
Failure to do so will often result in flickering effects in the GPI troffers.
You can also get flickering in the GPI troffers if the signal filter input feedthrough capacitor has been damaged.
So be careful when you solder to the signal filter tabs.

In a non-MRI installation, each master GPI can power satellite GPI units with daisy chained power and dimming control.
A 2x2 master can have up to 5 additional satellites, a 2x4 master can have 2, and a 4x4 master cannot have any satellites.


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📌Bruce Neville - Engineering Manager
☏ 1-620-213-4451 Direct Voice & SMS
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Everbrite Electronics Inc.
720 West Cherry Street
Chanute, Kansas 66720
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