BL18 - Power Supply and Battery Charging Unit

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Contents

1 Application

2 Characteristics and Features

3 Functions and Settings3.1 Mounting and Connection3.2 Application as stabilized Power Supply Unit3.3 Application as battery charger3.3.1 Charging according to IU-Characteristic3.4 Derating of the output

4 Technical Data

5 Order form

1 Application

The BL18 is a widely applicable DC - supply unitwhich is used as battery charger or also as stabilizedpower supply.

As charging unit it is used for charging, as well as formaintaining the fully charged condition of closed orgastight 24 V Pb-batteries. Simultaneous supply of DC-consumers (parallel operation) is possible. Operated inparallel with a battery or other consumer, the BL18guarantees the supply of the consumers up to the ratedoutput of the charging unit even after disconnection ofthe battery, for example during maintenance or for ex-change.The BL18 is short-circuit proof so that it is not neces-sary to shut down the charging unit during operationswhich could cause nearly a short-circuit (for instancestart of a diesel engine).

As stabilized power supply unit, the BL18 suppliesconnected consumers with a stabilized d.c. voltagewhich is adjustable within a range of 24 V to 27.5 Vor12 V to 24 V.

2 Characteristics and Features

• Input voltage 3 x 400 V AC +/- 15%1 x 230 V AC +/- 15%

• Safety according to VDE 0805 / EN 60950• High stability of output voltage• Low residual ripple• High efficiency• Screw type and plug-in connectors• Suppression of radio interferences

acc. to VDE 0875/ T11/EN 55011, class B• Interference immunity acc. EN 50082-2• Short-circuit and no-load proof• Compact housing• Low weight (1.9 kg)• DIN rail mounting• Power on LED

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3 Functions and Settings

The BL18 is equipped with a trimming potentiometerinstalled beside the bottom plug-in connector for adjust-ing the output voltage (see fig. 3.1). The output volt-age can be adjusted within a range of 24 V to27.5 V or 12 V to 14 V by means of a normal screwdriver. Turning it to the left reduces the output voltage,turning it to the right increases the output voltage. TheLED on the front plate indicates readyness for opera-tion.

A usgangO utput

A d j: 24 - 27 ,5 V12 - 14 V

Fig. 3.1: Connection terminals of the secondary side and potentiometer for adjusting output voltage

3.1 Mounting and Connection

In order to ensure optimal cooling, it is absolutely nec-essary to install the unit in the right position, i. e. inputterminals (L1/L2/L3/PE or L1/N/PE)) must be on topand output terminals (+/-) at the bottom.

A free space of at least 100 mm must be left aboveand below the BL18, and of at least 30 mm at bothsides.

Please ensure that the temperature of the incoming airdoes not exceed the admissible value of the ambienttemperature indicated in the technical data.Connection of the three-phase input voltage is to bemade according to the instructions printed on the hous-ing of the unit. For this no specific phase sequence hasto be observed. The primary side of the unit should beprotected with a three-pole L-miniature circuit-breakeror a three-pole motor protection switch (setting 2.5 A).During failure of one phase, operation of the unit is notpermitted. The protected earth (PE) of the BL18 mustbe connected with the protected earth of the switch-board. Installation must be done acc. to VDE 0100and VDE 0160.

Fig. 3.2: Connection to the mains

Attention!The existing safety rules at site must be observed dur-ing all installation and service jobs!

The plug-in connectors of the secondary side have twoparallel connection terminals per pole (+/-), it is, how-ever, also possible to use only one terminal for thesupply.

3.2 Application as stabilized Power Supply Unit

Used as stabilized power supply unit, the BL18 sup-plies consumers with a constant output voltage be-tween 24 V and 27.5 V DC or between 12 V and14 V, depending on the selected adjustment value.

The output voltage is stabilized up to the rated currentload value. If this value is exceeded, the output volt-age is reduced automatically.

Fig. 3.3: Limitation of current

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3.3 Application as battery charger

For charging at normal temperatures up to 30° C,most battery manufacturers recommend for lead acidbatteries a trickle charging voltage of 2.25 V per cell.From this results a trickle charging voltage of 27 V fora24 V lead acid battery. In case of higher ambienttemperatures, the charging voltages must be reducedfollowing the instructions of the battery manufacturers,whereas in case of external voltage losses they mustbe increased accordingly. The relay types BL18-400-24 and BL18-230-24 are set to 27 V DC output volt-age by manufacturer.

3.3.1 Charging according toIU-Characteristic

Charging is done acc. to a IU-characteristic (see fig.3.4). When batteries are discharged, a high currentof approx. 21 - 23 A flows in the first stage (I-charge).It is limited by the BL18. As soon as the charging volt-age reaches the set value (equalizing charging), transi-tion for charging at constant voltage takes place(U-charge). The charging current decreases until theunit supplies a trickle charging current, in addition tothe current necessary for connected consumers. Theadvantage of this charging procedure, compared tothe charging at constant current, is shown here. By re-duction of the current upon reaching the trickle charg-ing voltage, overcharge of the battery is prevented.Therefore, an inadmissably high water loss by gasingis avoided, which would occur, if a continued highcharging current flows, after the battery has been fullycharged.

Fig. 3.4: Charging acc. to IU-characteristic

3.4 Derating of the output

At an ambient temperature >60° C, the load capacityof the units is reduced acc. to the following diagram:

Fig. 3.5: Derating of the output

In order to avoid overheating of the units, consumerload must be reduced.

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4 Technical Data

General Data

Type: BL18

Permissible operating time: continuous operationConnection terminals: max. 2.5 mm² (wire connection)Type of cooling: convection coolingMaintenance: noneShort circuit: sustained short circuit proofNo-load: sustained no-load proofMounting position: wall mounting, input terminals on top, output terminals at bottom

Input Circuit (three-phase)

Input voltage : 3 x 400 V AC ±15% at Usec = 24 V DC/18 A,+15%/-10% at Usec = 27.5 V DC/18 A

Input rated current: 3 x 1.5 A (24 V type) / 3 x 0,8 A (12 V type)Frequency range: 47 - 63 HzInrush current: <50 APower factor cosϕ: 0.55 capacitiveFuse: three-pole miniature c.b. or motor protection switch (setting 2.5 A)

Input Circuit (single-phase)

Input voltage : 1 x 230 V AC ±15% at Usec = 24 V DC/18 A,+15%/-10% at Usec = 27.5 V DC/18 A

Input rated current: 4.4 A (24 V type) / 2.4 A (12 V type)

Output Circuit

Output voltage: 27 V DC ±1% / 13,5 V DC ±1% (preset by manufacturer)Setting range: 24 - 27.5 V (24 V type) / 12 - 14 V (12 V type)Max. output current: 18 ALimitation of current: typically 20 A, starting point at 18.5 ... 21.5 A

limit point at 20.0 ... 26.0 AOutput: 480 WResidual ripple: <100 mVEfficiency: 90%Max. power loss: 53 WLoad capacity of output terminals: ≤20 A at TU = 0°C up to +45°C

0.2 A- reduction/°C from +45°C to ≤17 A at TU = +60°C

Regulation

Mains regulation: <0.1% of the output voltage at Umains ±15%Load regulation: <0.1% of the output voltage between 0 and 20 ACorrection time: <2 ms at a load change from 10 to 90% of rated current,

overshooting <2%Mains failure bridging time: >5 ms at Umains = 400 V AC and Usec = 24 V DC / 16 A

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Rules and regulations

Suppression of radio interferences: VDE 0875 part 11, EN 55011 class BStatic discharge ESD, IEC 801-2: 8 kV contact discharge

15 kV air dischargeElectromagnetic fields, IEC 801-3: 10 V/mBurst IEC 801-4: 4 kV input

2 kV output, capacitive couplingSurge IEC 801-5: 4 kV asymmetric, 4 kV symmetric

Safety rules VDE 0805/11.93, EN 60950, IEC 950

Test voltage: 3 kV AC : all safety relevant components1.5 kV DC: finished product between primary and secondary side1.5 kV DC: finished product between primary and protection earth0.5 kV DC: finished product between secondary and protection earth

protection class: class IDegree of protection: IP20Discharge current: <0.75 mA (47 - 63 Hz mains frequency and Umains, max )

Operating data

Temperature range during operation: 0 to +70°C, with free convection during storage: -25 to +85°C

Derating of output: 2.5 %/K above +60°C (see Fig.3.5)

Housing

Dimensions (Width x Height x Depth): 240 mm x 130 mm (153 mm) x 86 mmSpace for convection: above and below the unit 100 mm, at the sides 30 mmWeight: approx.1.9 kgMounting: DIN-rail mounting acc.to DIN EN 50022-35

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Fig. 4.1: Housing dimensions

All dimensions in mm!

Please observe!A free space of at least 100 mm must be left above and below the BL18, and of at least 30 mm at both sides.

5 Order form

Power Supply and Battery Charging Unit BL18-

Input voltage:400 V three-phase230 V single-phase

400230

Output voltage:24 V (24 - 27,5 V DC)12 V (12 - 13,75 V DC)

2412

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