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MDS-D2/DH2 Series Instruction Manual
9.3 Explanation of Each Part of Power Backup System
9.3 Explanation of Each Part of Power Backup System
9.3.1 How to Set Rotary Switch and Dip Switches
The rotary switch (SW1) of the power backup unit is for selecting the regenerative resistor for the power backup unit to
be used. The dip switches (SW2, SW3) are for function selection of the power backup unit. The settings of these
switches are enabled when the power backup unit power is turned ON.
9.3.2 Transition of LED Display After Power Is Turned ON
When the power backup unit power has been turned ON, the unit will automatically execute self-diagnosis and initial
settings for operation, etc. The LEDs on the front of the units will change as shown below according to the progression of
these processes.
If an alarm occurs, the alarm No. will appear on the LEDs. Refer to section "9.4.1 LED display when alarm or warning
occurs" for details on the alarm displays.
(MDS-D/DH-PFU
SW1 SW2 SW3
1 2 3 4 5 6
(2)
(1)
(SW1)
MDS-D-PFU MDS-DH-PFU
0
1
R-UNIT6 5.0 2100
2
R-UNIT-7 1.4 2100
3 13
14
15
MDS-D-PFU MDS-DH-PFU
0
1
-
2
--
14
15
(SW2SW3)
SW2
1
2
3
4
SW3
5
OFF
ON
6
ON
(SW2SW3)
SW2
1
2
3
4
SW3
5
6
OFF
OFF
ON
3 to 13
*1: The switches are OFF when facing bottom as illustrated.
Power backup unit
Power backup unit function selection
Regenerative resistor selection for power backup unit
Function selection
switch
Description
Setting
Capacitor unit connection
Not used
Power failure detection time for
AC input voltage
(including open-phase detection
signal)
Power failure detection
sensitivity for AC input
voltage
Setting prohibited (All OFF) (*1)
Standard setting (60ms)
High-speed setting (20ms)
Standard setting
(120VAC: MDS-D-PFU)
(240VAC: MDS-DH-PFU)
High-sensitivity setting
(135VAC: MDS-D-PFU)
(270VAC: MDS-DH-PFU)
Rotary switch
(SW1)
Name of
regenerative
resistor
Resistance
value
[Ω]
Continuous
rating
[W]
Name of
regenerative
resistor
Resistance
value
[Ω]
Continuous
rating
[W]
Setting prohibited
Setting prohibited
Setting prohibited (*2)
Setting prohibited
Setting prohibited
*2: If you select this, the function selection error (Alarm 18) will occur in the power backup unit.
Not connect
Connect
Power backup unit
LED display
In initializing
Initializing completed
In ready ON
(In Charging)
Ready ON state
(Charge completed)
