Check For Shorts To Ground - MCi iControl User Manual

Construction Mode

Check for Shorts to Ground

Check for shorts to ground before powering up the system. Power must be OFF at the main
disconnect. If any shorts to ground are discovered, they must be corrected before proceeding.
A short to ground is defined as having a resistance of less than 20 ohms between the #1 (Com-
mon) bus and the terminal being tested.
Danger
Be certain that power is OFF at the main disconnect before proceeding.
Caution
Typically, the iLink cartop box has not been installed at this point. If the cartop box has
been installed and connected, it MUST be disconnected before checking for shorts in the
controller cabinet. This is easily done by simply unplugging all field-wired connectors in the
cartop box before checking for shorts to ground.
1. Using a standard screwdriver, temporarily disengage all fuses at the top of the iPower
box by turning them counterclockwise until they pop up. Don't place a cap on a fuse
holder without a fuse in it. The cap can get stuck and be hard to remove.
2. Disengage all fuses at the bottom of the iBox (just below the logo).
3. Release the screws that hold the iPower box
closed and open the enclosure. Disengage all
the fuses from the fuse block inside (towards
the top of) the iPower box by lifting them clear
of their sockets at one end.
4. Measure the resistance between the iBox #1
(Common) bus and terminals that have a field
connection (DZ down to SP4 on the left side of
the iBox).
5. Measure the resistance between the #2
(120VAC) bus terminals and the #1 bus.
6. Measure the resistance between the #3 (110VDC) bus terminals and the #1 bus.
7. Check for shorts to ground on motor power terminals L1, L2, and L3.
8. Check for shorts to ground on brake terminals B1 and B2.
9. If no shorts to ground are discovered, re-engage the fuses. Refer to the job prints for fuse
location if necessary.
2-16 Manual # 42-02-2222