When connecting the CCN communication bus to a sys- tem element, a color code system for the entire network is recommended to simplify installation and checkout. The fol- lowing color code is recommended:
SIGNAL TYPE | CCN BUS CONDUCTOR | COMM1 PLUG | |
INSULATION COLOR | PIN NO. | ||
| |||
+ | Red | 1 | |
Ground | White | 2 | |
− | Black | 3 |
If a cable with a different color scheme is selected, a simi- lar color code should be adopted for the entire network.
At each system element, the shields of its communication bus cables must be tied together. If the communication bus is entirely within one building, the resulting continuous shield must be connected to ground at only one single point. See Fig. 31. If the communication bus cable exits from one build- ing and enters another, the shields must be connected to ground at the lightening suppressor in each building where the cable enters or exits the building (one point only).
To connect the 23XL chiller to the network, proceed as follows (Fig. 31):
1.Cut power to the PIC control center.
2.Remove the COMM1 plug from the processor module.
3.Cut a CCN wire and strip the ends of the RED, WHITE, and BLACK conductors.
4.Using a wirenut, connect the drain wires together.
5.Insert and secure the RED wire to Terminal 1 of the COMM1 plug.
6.Insert and secure the WHITE wire to Terminal 2 of the COMM1 plug.
7.Insert and secure the BLACK wire to Terminal 3 of the COMM1 plug.
8.Mount a terminal strip in a convenient location.
9.Connect the opposite ends of each conductor to separate terminals on the terminal strip.
10.Cut another CCN wire and strip the ends of the conductors.
11.Connect the RED wire to the matching location on the terminal strip.
12.Connect the WHITE wire to the matching location on the terminal strip.
13.Connect the BLACK wire to the matching location on the terminal strip.
Install Field Insulation
Protect insulation from weld heat damage and weld splat- ter. Cover with wet canvas cover during water piping installation.
When installing insulation at the job site, insulate the fol- lowing components:
·compressor motor
·cooler shell
·cooler tube sheets
·suction piping
·motor cooling drain
·oil reclaim piping (Frame 1 and 2 machines only)
·cooler liquid inlet piping
·hot gas bypass piping (if applicable)
·economizer and economizer piping (if applicable)
Insulation of the waterbox covers is applied only at the jobsite. When insulating the covers, make sure there is ac- cess for removal of waterbox covers for servicing (Fig. 32 and 33).
Depending upon humidity conditions, ®eld insulation of the condenser's bottom half may be required when the ma- chine is not operating.
30
