Optional Functionalities - Trane TCAA Series Installation, Operation And Maintenance Manual

Packaged air-cooled magnetic bearing chiller

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Table Of Contents

Table of Contents

Operating Procedures

Compressor Staging Valve Control

All compressors Staging Valves controls can be accessed

from compressors screen Main Menu →Comp button →

Staging button. Controls are available for Tech level HMI

users and above.

Each Staging Valve controls consist of two components:

1. Mode selector

2. Valve status light

Figure 28. Staging valves control screen

As per control options, each Staging Valve can be in one of

the modes:

1. Off – staging valve is always off regardless of other

conditions.

2. On – staging valve is forced on. Used mostly for

troubleshooting or maintenance purposes.

3. Auto – staging valve is controlled automatically as

compressor cycles through its states.

Compressor Staging Priority

Compressor staging priority defines the order by which the

compressors are staged up. By default, this priority is by

runtime, but a Tech-Level user can change this priority with

the following options:

•

Runtime (default selection) – compares the runtimes of

the compressors:

Table 16. Chiller control system Optional Functionalities list

Function

Monitor and Control fan banks (when in free cooling) and free cooling modulation valve

Free Cooling

Pump and Plant controls

Data Logging

Master / Slave

Controller option

Economizer

Hot Gas Bypass Valve

Low-Lift Application

Monitor and Control evaporator and condenser pumps functions

Displays chillers / compressors key data logged to CSV files

Monitor and Control multiple chillers primary/secondary functions

Select the model of Main Chiller PLC

Monitor and Control compressors economizers functions

Monitor and Control compressors Hot Gas Bypass functions

Allows chiller to operate at pressure ratios less than 1.5. Adds a refrigerant pump to

push liquid refrigerant to compressor motor cooling ports.

–

On stage up – the lowest runtime is started.

–

On stage down – the highest runtime is stopped.

•

Default – Default as a named option refers to the built

order of the chiller. For example, compressor labelled

Compressor #1 is first on and last off; Compressor

labelled Compressor #2 is second on and second last

off.

•

User – using the following pop-up, the user can define

the priority. Once the selections have been made, the

user must commit the changes. There can be no

duplicates and, user cannot define a priority to

compressor that is not on part of the chiller. Any errors

to the selection will prevent commit function with

suitable messages to user.

•