Carrier 30XW325-400 manual Guide specifications cont

Guide specifications (cont)

compressor discharge piping and waterbox heads because of high temperature.

F.Refrigeration Components:

Refrigerant circuit components shall include oil sep- arator, high and low side pressure relief devices, dis- charge and liquid line shutoff valves, filter drier, moisture indicating sight glass, expansion valve, refrigerant economizer (unit sizes 350, 400), and complete charge of compressor oil. The units shall have a complete operating charge of refrigerant HFC-134a.

G.Controls:

1.Unit controls shall include the following mini- mum components:

a.Microprocessor with non-volatile memory. Battery backup system shall not be accepted.

b.Separate terminal block for power and controls.

c.Separate 115-v power supply to serve all controllers, relays, and control components.

d.ON/OFF control switch.

e.Replaceable solid-state controllers.

f.Pressure sensors installed to measure suction, oil, economizer, and discharge pressure. Thermistors installed to measure evaporator entering and leaving fluid temperatures.

2.Unit controls shall include the following functions:

a.Automatic circuit lead/lag.

b.Capacity control based on leaving chilled fluid temperature and compensated by rate of change of return-fluid temperature with temperature set point accuracy to 0.1° F (0.05° C).

c.Limiting the chilled fluid temperature pulldown rate at start-up to an adjustable range of 0.2° F to 2° F (0.1 to 1.1° C) per minute to prevent excessive demand spikes at start-up.

d.Seven-day time schedule.

e.Leaving chilled fluid temperature reset from return fluid and outside air temperature.

f.Chilled water and condenser water pump start/stop control.

g.Chiller control for parallel chiller applications without addition of hardware modules and control panels (requires thermistors).

h.Timed maintenance scheduling to signal maintenance activities for strainer maintenance and user-defined maintenance activities.

i.Single step demand limit control activated by remote contact closure.

H.Safeties:

Unit shall be equipped with thermistors and all nec- essary components in conjunction with the control system to provide the unit with the following protections:

1.Loss of refrigerant charge.

2.Reverse rotation.

3.Low chilled fluid temperature.

4.Motor overtemperature.

5.High pressure.

6.Electrical overload.

7.Loss of phase.

8.Loss of chilled water flow

I.Diagnostics:

1.The control panel shall include, as standard, a display:

a.Touch screen display consisting of ¼ VGA LCD (liquid crystal display) with adjustable contrast and backlighting.

b.Display shall allow a user to navigate through menus, select desired options and modify data.

2.Features of the display shall include:

a.Display shall be customizable and allow up to 72 data points.

b.Display shall support both local equipment or network made for remote mount.

c.Display shall allow access to configuration, maintenance, service, set point, time sched- ules, alarm history and status data.

d.Display shall have one button for chiller on/ off.

e.Display shall include three levels of password protection against unauthorized access to configuration and maintenance informa- tion, and display set up parameters.

f.Display shall allow for easy connection of a portable hand held technician tool to access information and upload and/or download chiller settings.

g.Display shall be compatible with the Carrier Comfort Network® (CCN) system and pro- vide network alarm acknowledgement or indication and provide capability to fully monitor and control chiller.

h.Display alarms and parameters shall be capable of being displayed in full text.

i.Display shall be capable of displaying the last 50 alarms and will store a snapshot of a minimum of 20 status data parameters for each alarm.

j.Compressor run hours.

k.Compressor number of starts.

l.Compressor current.

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