ACME Koolmaster PP20-VS2, Руководство пользователя, Страница: 39 / 48

39
KOOLMASTER PP20-VS2 rev.00
KOOLMASTER PP20-VS2
12.
ALARMS
When an alarm occurs, the controller lights
up the alarm pilot light, displays letters
“AL”
on the LED display, and post the alarm con-
dition into the alarm log menu. Some user-
defined alarm conditions may also activate
the alarm relay.
The table on the right gives a list of all pos-
sible alarm conditions. Refer to section 12.3
to specify which of these alarm conditions
must activate the alarm relay.
DISPLAY MEANING
Low Temp
Alarm
Low temperature alarm
High Temp
Alarm
High temperature alarm
Low Pressure
Alarm
Low static pressure alarm
High Pressure
Alarm
High static pressure alarm
Probe #1-8
Defect
A temperature probe is
defective
Outside Probe
#x Defect
Outside probe #x is
defective
Whisker
Switch Defect
The Whisker switch is
defective
Water Spill Water consumption too
high
Lo/Hi Water
Usage
The water consumption
of the last 24h is too low
or to high compared to
the water consumption of
the 24h that precede.
SP Probe
Defect
The static pressure sen-
sor is defective
Inside RH
Probe Defect
The indoor humidity
probe is defective
Outside RH
Probe Defect
The outdoor humidity
probe is defective
Relay panel
comm. Error
Communication is disrupt-
ed between the control-
ler and the relay panel.
Inlet potenti-
ometer defect
The potentiometer is
defective.
Feeder 1-2
run time ex-
ceeded
A feeder has been run-
ning continuously on a
too long period of time.
Missing zero
crossing
Problem with the zero-
crossing signal of the
variable fans
Another alarm situation occurs when power to
the controller fails. In this case, the alarm relay
is activated. When the alarm relay is activated,
the normally open contact (
) closes.
12.1. Alarm Log
Select: 1.
Current Conditions (Main Menu)
Alarm Log
Alarm
conditions
Details
about
the selected
alarm
Alarm Log
Use to navigate
Logged at Jan 01 200X
12:00 A
Temperature High °F
Probe 5 Defective
Probe 4 Defective
12.2. Alarm Conditions
Temperature Alarms
The diagram below shows how temperature
alarms are detected.
When the average room temperature exceeds
the high temperature alarm setting, a high
temperature alarm is set off. When the aver-
age room temperature decreases below the
low temperature alarm setting, a low tempera-
ture alarm is set off. Although these settings
are entered by the user as absolute values,
they are defined based on the room set point.
They are thus automatically adjusted if the
set point changes.
The situation is slightly different when the
outside temperature is greater than the room
set point. In this case, the outside tempera-
ture becomes the reference point (instead of
using the set point as a the reference). This
means an alarm is set off when the room
temperature reaches Outside Temperature
+ High Alarm Offset (the offset being the
difference between the high alarm tem-
perature setting and the set point). A third
parameter, called the critical temperature,
is defined to continue monitoring the indoor
temperature for high temperatures. When the
indoor temperature reaches the critical high
temperature (defined as an absolute value),
an alarm is set off.
Detection of
Temperature Alarms
Room T°
Alarm
Limits
Hi T°
limit
Hi T°
alarm
Lo T°
limit
Set
Point
Temperature Alarms in Clean Mode
The controller can monitor low temperature
alarms when it is in clean mode. If this alarm
condition is used, the controller sounds an
alarm when the temperature falls below low
alarm limit that is associated to the clean
mode.
The low alarm limit used in clean mode is re-
lated to the clean mode set point; this means
the alarm limit is automatically adjusted when
the clean mode set point changes.
Static Pressure Alarms
The controller can sound an alarm when the
static pressure (SP) level exceeds high or low
pressure limits for a certain period of time.
Feeder Alarm
The controller sets off an alarm if a feeder
runs continuously on a too long period of
time. When this type of alarm occurs, the
relay associated with the problematic feeder
opens in order to stop the feeder motor. This
alarm condition is optional.
Missing Zero Crossing Alarm
If the zero-crossing signal of the variable
output fails, the variable-speed fans will au-
tomatically stop running. To overcome this
problem, the controller can force these fans to
restart running at full speed when this type of
failure occurs: if the fan stage in use requries
the variable fans to run at full speed, the
controller will force the variable fans to stay
on without interruption; if the stage asks for
a variable speed, the controller will activate
the variable-speed fans in timer mode (default
timer = 30 seconds at 100% and 30 seconds
Off). This zero-crossing timer can be modi-
fied by the integrator in the installation menu
(factory password is required).