Daikin WGZ030DW, Инструкция по установке, эксплуатации и обслуживанию

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IOM 1322-1 • WATER-COOLED SCROLL COMPRESSOR 48 www.DaikinApplied.com
Unit Controller
Manual Compressor Control
The operator can manually enable and disable individual
compressors. When a compressor has been disabled it is
considered unavailable to start in the staging logic. With
Manual Compressor control it is possible to take a damaged
compressor offline while the remaining compressors on the
circuit can still provide some cooling.
A running compressor cannot be disabled until it has been
shutdown. If both of the compressors on a circuit have been
disabled then the circuit is disabled. If both circuits have all of
their compressors disabled, the Unit state will remain “Off”.
Normal Circuit Shutdown
If a condition arises that requires a circuit to shut down, but it
is not an emergency situation, then the circuit will do a pump
down. A normal circuit shutdown will be initiated when any of
the following occur:
• Unit State = Pump Down
•
Circuit Switch = Off
• Low Ambient Lockout
• A normal stage down occurs, and only one compressor
on the circuit is running
• Unit mode = Ice AND the ice set point is reached
Pump Down Procedure
• If both compressors are running, shut off the appropriate
compressor based on sequencing logic
• With one compressor left running, turn off hot gas output
and liquid line output
• Keep running until evaporator pressure reaches the pump
down pressure, then stop compressor
• If evaporator pressure does not reach pump down
pressure within two minutes, stop compressor and record
a Failed Pumpdown event in the Event Log.
Liquid Line Solenoid
The liquid line output shall be on any time a compressor on the
circuit is running and the circuit is not performing a pump down.
This output should be off at all other times.
Hot Gas Bypass Solenoid
This output shall be on when one compressor on the circuit
is running and the circuit is not performing a pump down. The
output should be off at all other times including the delay time
described below.
The hot gas bypass valve opening will be delayed for Hot Gas
Bypass Time set point seconds (the default is 30 seconds)
when the first compressor starts on each circuit. This delay
allows sufficient condenser pressure to build up.
EXV Control
The EXV control logic is active regardless of the expansion
valve type setting. While a circuit is in the run state, the EXV
controls suction superheat. The superheat target is 8°F. PID
logic will be used to control the superheat to the target value.
Any time the circuit is not in the run state, the EXV position
should be 0.
EXV Control Range
The table below shows the EXV range based on the number of
compressors running and number of compressors on unit.
Manual EXV Control
The EXV position can be set manually. Manual control can only
be selected when the circuit is in the run state. At any other
time, the EXV control set point is forced to auto.
When EXV control is set to auto, the manual EXV position
setting follows the auto control position.
When EXV control is set to manual, the EXV position is
equal to the manual EXV position setting.
Using the Controller
Getting Started
There are two basic procedures to learn in order to utilize the
MicroTech II controller:
• Navigating through the menu matrix to reach a desired
menu screen and knowing where a particular screen is
located.
• Knowing what is contained in a menu screen and how
to read that information or how to change a set point
contained in the menu screen.
Navigating Through the Menus
The menus are arranged in a matrix of screens across a top
horizontal row. Some of these top-level screens have sub-
screens located under them. The general content of each
screen and its location in the matrix are shown in Figure 10. (A
detailed description of each menu begins on page 53.) There
are two ways to navigate through the menu matrix to reach a
desired menu screen.
One is to scroll through the matrix from one screen to another
using the four ARROW keys. The other way is to use shortcuts