1. Principal circuit and working principle .
Buffer capacitors are charged under normal conditions (high quantity of energy can be
stored by using higher voltage). In case of mains voltage fault, this energy is transferred
to feed the buffered loads.
The bridging time for mains voltage faults is more than 200 ms with 20 A buffering current.
According to statistics this time is enough to give more than 80% certainty for unbroken
load current.
This equipment is intended for use in a Pollution Degree 2 environment, in overvoltage
Category II or I applications.
3. Features
Output / Input terminal:
Conductor sizes
Solid 4 mm² / 11 AWG
Stranded 4 mm² / 11 AWG
Stranded with ferrule without / with plastic sleeve 4 mm² / 11 AWG
Ferrule minimum lenght must be ≥10 mm
Tightening torque: 0,5 - 0,6 Nm / 5 - 7 lb. in.
Use 60/75°C copper conductors only
Signal terminal:
Conductor sizes
Solid 0,25 - 1,5 mm² / 24 - 16 AWG
Stranded 0,25 - 1,5 mm² / 24 - 16 AWG
Stranded with ferrule without / with plastic sleeve 1,5 mm² / 16 AWG
Ferrule minimum lenght must be ≥10 mm
Tightening torque: 0,4 Nm / 3,5 lb. in.
Use 60/75°C copper conductors only
Buffer mode: A (Uin = -1 VDC (factory default)) or B (< 22,5 VDC).
Operation indicator; Bi-coloured LED (see table “Operating modes”).
4. Location
The Buffer Module is cooled by natural convection. It is important to maintain clearance
to other components as much as possible to ensure best performance and long term
stability. The ambient temperature should be measured on the underside of the unit.
There will be an increase of 25°C at the top. If natural convection is restricted, forced
cooling should be used. Mounting should comply with EN 60950-1 point 4.7 and 4.6.1.
Protection class of the case IP20 (EN 60529).
5. Mounting
The rail should be fixed solidly so that it cannot twist when mounting or removing the
unit. Mounting instructions , Removing instructions .
6. Switching on
Factory set, ready to use, check the connection diagram for buffered and unbuffered
use.
7. Signal connections
Signal outputs: Optocouplers,
A = Active; low ohmic while buffering,
R = Ready; low ohmic while Buffer Unit is fully charged.
Current max. 15 - 20 mA (internal current limitation), voltage drop 1 - 3,5 VDC.
Signal input: Optocoupler,
I = Inhibit; ‘LOW’ input signal initiates Buffer Unit shutdown and energy discharge.
Current 1,5 - 2 mA, sinking.
Isolation voltage: 500 VAC against input paths. Signal input and outputs are protected
against short-circuit, open circuit and wrong polarity.
Note: Inhibit signal will stay on for 2 minutes after activated.
8. Activation threshold.
Mode A : Uin -1 VDC;
Buffering starts if terminal voltage decreases by more than 1 VDC and faster than 0,5
V/s. Voltage is kept at that level.
Mode B : Fixed - 22,5 VDC;
Buffer starts if terminal voltage is < 22,5 VDC, voltage is kept at 22,5 VDC.
9. Operating modes and .
10. Standards
Electrical safety EN 60950-1, UL 508, SELV
EMC EN 61000-6-2
EN 61000-6-3
Emissions EN 55022, class B
We reserve the right to change this specification.
In order to take the best advantage of the
features that this Maintenance-Free Buffer
Module has to oer and to ensure long
term reliability for your equipment, please
read these instructions carefully before
installation and use. They should be
retained for future reference.
MB Cap 20/24
Art. No. 85394
OPERATING INSTRUCTIONS
2. Technical specification, Art. No. 85394
V 1.2
Nominal voltage 24 VDC (SELV / PELV)
Input voltage range 23 - 30 VDC
Input current < 85 mA / idle - < 500 mA / charging
Protection against reverse polarity Yes
Transient surge protection < 35 VDC
Charging delay time < 100 ms
Charging time 20 - 45 s
Charging current < 500 mA
Output voltage 24 VDC
Output voltage range 22 - 28 VDC
Buffer voltage Uin -1 VDC or < 22,5 VDC
Output current, continuous 20 A
Current limitation 26 A
Buffering time (Hold-up time) 0,2 s / 20 A / 24 VDC - 4 s / 1 A / 24 VDC
Power consumption 1,7 W / ready
Efficiency > 95% at 20 A
Residual ripple voltage < 200 mV
p-p
Parallel connection Possible
Relative humidity 5 - 95%, no condensing
Operating temperature 0°C - +55°C
Storage temperature -25°C - +85°C
Protection class, case, EN 60529 IP20
Dimensions W x H x D x TA; Weight 62 x 115 x 145 x 20 mm; 0,66 kg
5
6
8
7
54
115
2
57
58
5
62
1
2
3
4
9
10
TA
Output
+
-
Ready:
Charging:
20A
+
-
Input
DC 23- 30V
ART. NO. 85394
Disc harging:
A
R
I
A
BUFFER MODE
R I+
GREEN blinking
GREEN continuou s
RED
MB Cap
A
B
A Uin- 1V
B 22.5V
- Inhibit
- Ready
- Active
AC OutputInput
Power
supply
Buffer unit/units Unbuffered
Load
Art. No. 85394
Buffered
Load
Buffered
Load
Art. No. 85394
OutputInput
> 2kOh m
R > 2kOhm
+ A R I
Buffer Unit
Power
supply
Buffer unit/units
DC - UNBUFFERED
DC - BUFFERED
AC
+ +
DC - BUFFERED
Programmable Logic
Input
GND
Coil resistance
Relay
+ A R I
+
+
R
AC Power
Supply
LED
AC Power
Supply
ON/OFF
Buffer Unit
L N PE
L N PE
Reverse
polarity
protection
Inrush
current
limiter
Decoupling
Buffered/
Unbuffered
Charger Buffer
Capacitor
Buffer
Capacitor
shutdown
Buffering
Input
Output
Threshold voltage
selection
Uin-1V
22.5V
Current
Limiter
Current
Limiter
15kohm
RED GREEN
Status signal
Max. 35VDC
Hold up time
Time / s
Buffer charging time
Buffering capacity
Charging time / s
Inhibit
Active
Ready
-
-
- - +-+-
+
-
+-
+-+-+-
+
+
-
-
+
-
min.
typ.
min. typ. max.
100%
80%
60%
0%
40%
20%
0 20 40
11
12
05 252010 15
0
1
2
3
4
5
6
Buffering current / A
15mA
15mA
+
Control logic
Input/Output Voltage control
E222272
1VD7
IND.CONT.EQ
Operating
Modes Current Time Led
Indicator Output
Active
Output
Ready
Buffer
capacitor
Buffer
charging
< 500 mA 20 - 45 s Green / Blinking 2,5 Hz high ohmic high ohmic charging
Idle < 85 mA - Green / continuous high ohmic fully chargedlow ohmic
Buffer
operation
0 - 20 A see
diagram
Red / continuous high ohmic bufferinglow ohmic
Inhibit mode < 85 mA 120 s Green 0,1 s / 1 s high ohmic high ohmic discharging
1
2
3
4
8
6
5
9
11 12
10
7
