Power Connection and Distribution

FORM 201.18-EG1

6.Display Data: Chiller liquid return and leaving tem- peratures, ambient, lead compressor identifica- tion and lead/lag delay, clock and schedule, (vari- able) out of range, remote input indication, chilled liquid reset setpoint, leaving liquid pull-down rate setpoint, leaving liquid error (deviation from set- point), and history data for last six shutdown faults. Compressor suction, discharge, and oil pressures and temperatures, suction and discharge super- heats, percent of full-load motor current, operat- ing hours, starts, and anti-recycle timer status. Status Messages for manual override, unit switch off, compressor run, run permissive, remote con- trolled shut down, no cooling load, daily/holiday shut down, anti-recycle/anti-coincident timer, high pressure low suction temperature limit.

7.System Safeties: Shall cause individual compres- sor systems to perform auto-reset shut down; manual reset required after the third trip in 90 minutes. Includes: high discharge pressure or temperature, low suction pressure, high / low motor current, high pressure switch, high / low differential oil pressure, high oil temperature, and motor protector. Compressor motor protector shall protect against damage due to: low or high input current, phase reversal (reverse rotation), current unbalance, phase loss, thermal overload of wind- ings, and low voltage.

8.Unit Safeties: Shall be automatic reset and cause

compressors to shut down if: high or low ambi- ent, low leaving chilled liquid temperature, under voltage, and flow switch operation. Contractor shall provide flow switch and wiring per chiller manufacturer requirements.

9.Alarm Contacts: High or low ambient, low leaving chilled liquid temperature, low voltage, low bat- tery, and (per compressor circuit): high discharge pressure or temperature, low suction pressure, low or high motor current, low or high differential oil pressure, and high oil temperature.

E.Manufacturer shall provide any controls not listed above, necessary for automatic chiller operation. Mechanical Contractor shall provide field control wir- ing necessary to interface sensors to the chiller con- trol system.

2.06POWER CONNECTION and DISTRIBUTION

A. Power Panels:

1.NEMA 3R/12 (IP55) rain/dust tight, powder painted steel cabinets with hinged, latched, and gasket sealed outer doors equipped with wind struts for safer servicing. Provide main power connection(s), compressor and fan motor start contactors, current overloads, and factory wiring.

2.Field power supply wiring connections shall be to a single power center on the chiller, shall be 3 phase of scheduled voltage, and shall connect to terminal blocks per each of the two motor control panels. Separate disconnecting means and/or ex- ternal branch circuit protection (by Contractor) re- quired per applicable local or national codes.

3.Provide two electrically separate, adjacent motor control center cabinets, with independent doors and separated by a steel panel, for compressor and fan motor power distribution components.

B.Exposed compressor and fan motor power wiring shall be routed through liquid tight conduit.

2.07ACCESSORIES and OPTIONS

Some accessories and options supercede standard product features. Your YORK representative will be pleased to provide assistance.

A. Microprocessor controlled, Factory installed Wye- Delta compressor motor starters for reduced com- pressor inrush start current. Two-compressor ma- chines with Single-Point Power connection and equipped with Star-Delta compressor motor start must also include factory provided circuit breakers in each motor control center. All 3 & 4 compressor machines equipped with Star-Delta compressor mo- tor start must also include factory provided circuit breakers in each motor control center.

B. Power Supply Connections:

1.Two Compressor Machines –

a.Multiple Point with Individual System Circuit Breakers or Non-Fused Disconnect Switches: Two Field provided branch circuits shall con- nect to Individual System Circuit Breakers or Non-Fused Disconnects per compressor on each of the two motor control centers, with lockable external handles on doors in compli- ance with Article 440-14 of the N.E.C.

b.Single-Point Terminal Block or Non-fused Dis- connect Switch: Field provided branch circuit shall connect to single-point Terminal Block or Non-Fused Disconnect with lockable exter- nal handle in compliance with N.E.C. Article 440-14, with Factory provided interconnect- ing wiring to (optional Individual System Cir- cuit Breakers, and) compressor motor start components in each of two motor control cen- ter cabinets.

c.Single-Point Circuit Breaker: Field provided branch circuit shall connect to Single-Point Cir- cuit Breaker with Lockable External Handle (in compliance with Article 440-14 of N.E.C.)

YORK INTERNATIONAL