Daikin RDT-135c Installation And Maintenance Manual page 122

Maintenance: Control Panel Components
Phase Voltage Monitor (PVM) (see page 88)
The phase voltage monitor is designed to protect three-phase
loads from damaging power conditions. A microprocessor-
based voltage and phase sensing circuit constantly monitors
the three-phase voltages to detect harmful power line
conditions. When a harmful condition is detected, its output
relay is deactivated after a specified trip delay (Trip Delay).
The output relay reactivates after power line conditions return
to an acceptable level for a specified amount of time (Restart
Delay). The trip and restart delays prevent nuisance tripping
due to rapidly fluctuating power line conditions.
Other features:
• LED display to indicate status (see
– Loss of phase
– High or low voltage
– Voltage unbalance
– Phase reversal
– Rapid cycling
– Standard 1 to 500 second variable restart delay (see
Figure 124)
• Standard 2% to 8% variable voltage unbalance (see
Figure 124)
• Standard 1 to 30 second trip delay (see
120
!
in Figure 124)
#
in
$
in
%
in Figure 124)
Figure 124. Phase voltage monitor
Standard 2%–8%
variable voltage
unbalance
Standard
1–500 second
variable
restart delay
Standard
1–30 second
trip delay
4
LED display
1
IM 738-2