iPECS eMG800
Hardware Description and Installation Manual
Issue 1.8
23
3.6
Power Supply Unit Wiring
Each KSU is equipped with a Power Supply Unit (PSU) that converts AC power to the DC voltages required by
the system. The DC voltages are distributed to the various boards in the cabinet by the backplane wiring
under control of the MPB. For PSU specifications see section 3.6.3.
The PSU in each cabinet should be connected to a common Earth or Frame ground and, if Battery Back-up
operation is required, each PSU should be connected to a Battery Back-up circuit. Each PSU also requires a
separate connection to AC power.
NOTE: Proper Power-up and down sequence
Turn off the PSU in the EKSU(s) then turn off the PSU in the BKSU. If the PSU in the BKSU is turned
off first, the system will automatically remove power from the EKSU.
The 1st and 2nd KSUs will work independent of the 3rd KSU (power shut-Off).
The 1st KSU will work independent of the 2nd KSU (powered-Off); however, the 3rd KSU cannot work
without the 2nd KSU powered-On.
It is recommended that the iPECS eMG800 be reset if the PSU in an EKSU is power cycled or turned
OFF.
3.6.1
Frame Ground Connection
Proper grounding minimizes the affect of power induced and RF noise, and reduces the risk of damage or
injury in case of a power cross or lightning strike. Be sure to comply with applicable local regulations regarding
grounding of equipment. To ground the system, at each KSU,
1)
Assure the system is not connected to AC power.
2)
Loosen the Ground lug screw by turning the screw counter-clockwise to loosen, as shown in Figure
3.6.1-1.
3)
Strip approximately 15mm (1/2 inch) of insulation from the end of the ground wire. A UL1015
AWG #18 (1.0mm) green/yellow insulated copper wire should be used with a recommended length
of 1 meter (3.28 feet) or less.
4)
Insert the grounding wire in the ground lug and tighten the screw.
5)
Then connect the grounding wire to an appropriate ground source. A cold water pipe with no
insulated joints is often an acceptable ground.
Figure 3.6.1-1 Grounding the KSU
