Daikin IOM 1322-1, Installation, Operation And Maintenance Manual

Page: 41 / 80

Unit Controller
www.DaikinApplied.com 41 IOM 1322-1 • WATER-COOLED SCROLL COMPRESSOR
Control
Source Set
Point
Mode
Input
Keypad
Entry
BAS
Request
Available
Modes Set
Point
Unit Mode
X X X X COOL COOL
X X X X COOL w/
Glycol
COOL w/
Glycol
SWITCHES OFF X X COOL/ICE w/
Glycol
COOL w/
Glycol
SWITCHES ON X X COOL/ICE w/
Glycol
ICE w/Glycol
KEYPAD X COOL
w/Glycol
X COOL/ICE w/
Glycol
COOL w/
Glycol
KEYPAD X ICE w/
Glycol
X COOL/ICE w/
Glycol
ICE w/Glycol
NETWORK X X COOL COOL/ICE w/
Glycol
COOL w/
Glycol
NETWORK X X ICE COOL/ICE w/
Glycol
ICE w/Glycol
X X X X ICE w/Glycol ICE w/Glycol
X X X X TEST TEST
Unit Test Mode
The unit test mode allows manual testing of controller outputs.
Entering this mode requires the following conditions:
• Unit Switch = OFF
• Manager password active.
• Available Unit Mode set point = TEST
A test menu can then be selected to allow activation of the
outputs. It shall be possible to switch each digital output ON or
OFF and set the analog outputs to any value.
Circuit Available
A circuit is available if the circuit switch is in the on position
and no circuit alarms are active. Timers that delay startup or
staging of a circuit do not render it unavailable.
Power Up Start Delay
After powering up the unit, the motor protector modules may
not reset for up to 150 seconds. After the control is powered
up, no compressor can start for 150 seconds. Motor protect
inputs are ignored during this time so as to avoid tripping a
false alarm.
Ice Mode Start Delay
An adjustable start to start ice delay timer will limit the
frequency with which the chiller may start in Ice mode. The
timer starts when the first compressor starts while the unit
is in ice mode. While this timer is active, the chiller cannot
restart in Ice mode. The time delay is user adjustable. The ice
delay timer may be manually cleared to force a restart in ice
mode. A set point specifically for clearing the ice mode delay
is available. In addition, cycling the power to the controller will
clear the ice delay timer.
Low Ambient Lockout
This feature is only available on air cooled units
(WaterCooled=Off).If the OAT drops below the low ambient
lockout set point, then all running circuits will do a normal stop.
Once the lockout has been triggered, no compressors will start
until the OAT rises to the lockout set point plus 5°F.
Unit State
The Unit will always be in one of three states. These states are
Off, Auto, and Pumpdown . Transitions between these states
are shown in the diagram on the following page.
T1: Off to Auto
Unit Enable = True AND
No Unit Alarm AND
IF Unit Mode = Cir 1 Available OR Cir 2 Available
T2: Auto to Pumpdown
Keypad Enable = Off OR
BAS Enable = Off OR
Remote Switch = Off OR
T3: Pumpdown to Off
Unit Alarm OR
Unit Switch Off OR
No Compressors Running
T4: Auto to Off
Unit Alarm OR
Unit Switch Off OR
No Compressors Running AND [Unit Mode = Ice AND Ice
Delay Active] OR
No Compressors Running AND [No Circuit Available]
Figure 21:
Unit State Diagram