Carrier 19XL CarrierComfort Network Interface , Check Starter

6. Be sure that fused disconnects or circuit breakers have

been supplied for the oil pump, power panel, and

pumpout unit.

7. Checkthat all electrical equipment and controls are prop-

erly grounded in accordance with job drawings, certi-

ﬁed drawings, and all applicable electrical codes.

8. Make sure that the customer’s contractor has veriﬁed

proper operation of the pumps, cooling tower fans, and

associated auxiliary equipment. This includes ensuring

thatmotors are properly lubricated and have proper elec-

trical supply and proper rotation.

9. Forﬁeld-installed starters only, test the chiller compres-

sor motor and its power lead insulation resistance with

a 500-v insulation tester such as a megohmmeter.(Use

a 5000-v tester for motors rated over 600 v.) Factory-

mounted starters do not require a megohm test.

a. Open the starter main disconnect switch and follow

lockout/tagout rules.

If the motor starter is a solid-state starter, the

motor leads must be disconnected from the starter

beforean insulation test is performed. The voltage

generated from the tester can damage the starter

solid-state components.

b. With the tester connected to the motor leads, take

10-second and 60-second megohm readings as

follows:

6-LeadMotor — Tie all 6 leads together and test be-

tween the lead group and ground. Next tie leads in

pairs, 1 and 4, 2 and 5, and 3 and 6. Test between

each pair while grounding the third pair.

3-Lead Motor — Tie terminals 1, 2, and 3 together

and test between the group and ground.

c. Divide the 60-second resistance reading by the

10-second reading. The ratio, or polarization index,

must be one or higher. Both the 10- and 60-second

readings must be at least 50 megohms.

If the readings on a ﬁeld-installed starter are unsat-

isfactory,repeat the test at the motor with the power

leads disconnected. Satisfactory readings in this sec-

ond test indicate the fault is in the power leads.

NOTE:Unit-mounted starters do not have to be meg-

ohm tested.

10. Tighten up all wiring connections to the plugs on the

SMM, 8-input, and PSIO modules.

11. Ensure that the voltage selector switch inside the power

panel is switched to the incoming voltage rating.

12. Onchillers with free-standing starters, inspect the power

panelto ensure that the contractor has fed the wires into

thebottom of the panel. Wiring into the top of the panel

can cause debris to fall into the contactors. Clean and

inspect the contactors if this has occurred.

CarrierComfort Network Interface — TheCarrier

Comfort Network (CCN) communication bus wiring is sup-

plied and installed by the electrical contractor.It consists of

shielded, 3-conductor cable with drain wire.

Thesystem elements are connected to the communication

bus in a daisy chain arrangement. The positive pin of each

system element communication connector must be wired to

the positive pins of the system element on either side of it;

thenegative pins must be wired to the negative pins; the sig-

nal ground pins must be wired to signal ground pins.

To attach the CCN communication bus wiring, refer to

the certiﬁed drawings and wiring diagrams. The wire is in-

sertedinto the CCN communications plug (COMM1) on the

PSIO module. This plug also is referred to as J5.

NOTE: Conductors and drain wire must be 20 AWG

(American Wire Gage) minimum stranded, tinned copper.

Individual conductors must be insulated with PVC, PVC/

nylon,vinyl, Teﬂon, or polyethylene. An aluminum/polyester

100% foil shield and an outer jacket of PVC, PVC/nylon,

chrome vinyl or Teﬂonwith a minimum operating tempera-

ture range of –20 C to 60 C is required. See table below for

cables that meet the requirements.

MANUFACTURER CABLE NO.

Alpha 2413 or 5463

American A22503

Belden 8772

Columbia 02525

When connecting the CCN communication bus to a sys-

tem element, a color code system for the entire network is

recommendedto simplify installation and checkout. The fol-

lowing color code is recommended:

SIGNAL

TYPE CCN BUS CONDUCTOR

INSULATIONCOLOR

PSIO MODULE

COMM 1 PLUG (J5)

PIN NO.

+RED 1

Ground WHITE 2

–BLACK 3

Check Starter

BE AWARE that certain automatic start arrangements

can engage the starter. Open the disconnect ahead of

thestarter in addition to shutting off the chiller or pump.

Use the instruction and service manual supplied by the

starter manufacturer to verify that the starter has been in-

stalled correctly.

The main disconnect on the starter front panel may not

deenergizeall internal circuits. Open all internal and re-

mote disconnects before servicing the starter.

Whenevera starter safety trip device activates, wait at least

30 seconds before resetting the safety. The microprocessor

maintains its output to the 1CR relay for 10 seconds to de-

termine the fault mode of failure.

MECHANICAL-TYPE STARTERS

1. Check all ﬁeld wiring connections for tightness, clear-

ance from moving parts, and correct connection.

2. Checkthe contactor(s) to be sure they move freely. Check

themechanical interlock between contactors to ensure that

1S and 2M contactors cannot be closed at the same time.

Check all other electro-mechanical devices, e.g., relays,

timers, for free movement. If the devices do not move

freely, contact the starter manufacturer for replacement

components.