N 03

Breaking capacity and behavior in normal use


 
PTL Power Supply
with resistive loads and inductive loads as Test Power Supply for testing the breaking capacity and the behaviour during normal use of switches resp. of plugs or socket-outlets for household and similar purpose with resistive-load rated currents up to 16 A, for tests with alternating voltages,
according to IEC 60669-1 :2007-01 18 and 19.1,
IEC 60884-1 2006-07 20 and 21,
however not for tests with direct current and with direct voltage.
Information N 03
Fundamental design
A power supply consists of the power unit which provides the adjustable test voltage, as well as the resistive load units and the inductive load units.
Operation as agreed
The power supply is primarily designed for
testing the breaking capacity and
testing the behaviour during normal use
for operation together with PTL Actuating Units of the series F 55. For this, both components are connected by means of a connecting lead with multiple connector. By this a reciprocal cut off of the components is ensured, in normal test duty as well as in case of fault, caused by the specimen or by one of the components.
It is possible to operate the specimen manually or to connect an other than a PTL Actuating Unit, but then, a cut off of the test voltage at the specimen is not ensured, and thus safety of staff is endangered.
Further employment
Further possible applications may be considered. For example checking electric lines and fuses is possible. Or an other than a PTL Actuating Unit can be connected.
The resistive and the inductive load units are floating. Therefore, they can be employed arbitrarily and also independently of the main transformer.
Design:
Trestle of rigid steel tubes with feet, suitable for transportation by forklift, slide bars for the slide-in modules, bottom, side walls and rear wall covered by steel sheets, lower part of the rear with intake opening(s), top with exhaust opening(s), both prepared for mounting air ducts, slide-in modules of rigid steel bars, front panels of anodized aluminium, steel parts structure varnished papyrus-white with stone-grey highlights.
For connection to three-phase 3 x 400 V / PE 50 Hz, mains connection cable with plug and inclusive fitting socket-outlet for wall fastening.
Available models:
One phase model, suitable for testing one single phase specimen (see top Fig.):
Power Supply 23,
1 x 20A, 275V AC, cos φ 1 - 0.3 ind.,
Article No.: N 03.23
Three phase model, suitable for testing up to three single phase specimens or for testing one three-phase specimen (see second Fig.):
Power Supply 43, 3 x 20A, 275V AC, cos φ 1 - 0.3 ind., Article No.: N 03.43
Abmessungen und Gewichte:
 
Article No.: Dimensions (width x depth x height in mm) Net weight
N 03.23 620 x 850 x 1 920 350 kg
N 03.43 1 760 x 850 x 1 920 995 kg
 
Description N 03
Slide-in modules
The individual components are accommodated in slide-in modules:
In the bottom slide-in module the A.C. power unit,
in the middle slide-in module the inductive load unit,
in the top slide-in module the resistive load unit.
The slide-in modules can be pulled out like a drawer. To prevent that the leads are stretched or that the slide-in modules will tip over, there are stops that can be fold back.
A. C. power unit
The A. C. power unit in the bottom slide-in module consists essentially of the main transformer.
The main transformer is primarily operated with the mains voltage. The secondary voltage is switchable by three rotary switches in coarse, medium and fine steps.
The main switch with pilot lamp(s) indicating the presence of mains voltage and an industrial multiple connector are in the bottom slide-in module, too. The connector is prepared for connection of switch or coupler actuating units. Four fuses serve as automatic cut-out for the control transformer, the control unit, the main transformer and the test circuit.
Data of the A. C. power unit
Design of the main transformer single phase dry transformer
wiring of the windings 4 separate windings
primary voltage and frequency 400 V, 50 Hz, without N
secondary voltage and power 0 up to 300 V, approx. 7.5 kVA
setting of the secondary voltage 3 rotary switches coarse, medium, fine
permissible secondary current 25 A at 50% duty ratio (cyclic duration factor)
continuous operation only allowed during sufficient ventilation
electronic overload release at approx. 28 A
 
Front panel view:
Resistive load unit
The resistive load unit serves for setting the test current. It consisting of heating grids, built into a duct in the top slide-in module. They can be switched by three rotary switches in coarse, me-dium and fine steps in any desired combination. The sum of the setting values on the rotary switches is equal to the current flowing through the specimen at 250 V and cos φ = 1. The resistive load unit is floating.
An axial flow fan serves for cooling the grids. It is monitored by a difference pressure switch.
Data of the resistive load unit
Design of the resistive load unit Heizgitter in quadratischem Schacht
wiring of the heating grids Parallelschaltung
setting of the test current 3 Drehschalter, grob, mittel, fein
setting range of resistive load unit 0,1 bis 25 A in Stufen von 0,1 A
permissible test current 25 A at 50% duty ratio (cyclic duration factor)
continuous operation only allowed during sufficient ventilation
electronic overvoltage release at approx. 285 V
 
Multifunctional Power Meter
The measuring instrument A2000 acquires voltages, current, frequency and phase displacement. It calculates active, reactive and apparent power, active and reactive energy, as well as the power factor for the individual phases based upon these values.
Factory settings for the indications:
Test Voltage in V Phase
Test Current in A Frequency in Hz
Power Factor cos φ (inductive)
With the setting buttons these indications can be changed: Selection of phase, of measured quantities, display of maximum and averaged values.
Inductive load unit
The inductive load unit is constituted by a fine step air-core inductor. It is switched over by means of three rotary switches in coarse, medium and fine steps. The three rotary switches may be set in any desired combination. The sum of the settings is corresponding to the inductivity.
In accordance with the test specifications the inductor has shunt resistors with a relatively high resistance, so that only about 1 % of the current flows through the shunt resistors.
The inductive load units are floating.
Data of the inductive load unit
Design of the fine step air-core inductor 3 separate windings of copper wire
wiring of these 3 windings connected in series
internal switching over of each winding by step switches
setting of the inductance 3 rotary switches coarse, medium, fine
permissible current 25 A at 50% duty ratio (cyclic duration factor)
continuous operation only allowed during sufficient ventilation
auxiliary resistors, shunted for approx. 1 % of the inductor current
electronic overvoltage release at approx. 275 V
 
Front panel view
Cooling
A fan is mounted at the lower end of the duct accommodating the heating grids. It presses the cooling air through the heating grids. It draws off the air from the internal and external surfaces of the inductor and the air heated by the main transformer as well.
The cooling air is drawn across the intake openings from the laboratory room. An air filter serves to prevent pollution of the components built in. The exhaust air is blown out upwards across a square exhaust opening.
If the air should be drawn in from outside and / or if the warm exhaust air gets annoying in the laboratory, intake and exhaust ducts are to be mounted. The ducts should have sufficient cross section in order to keep the air resistance low. The existing tapped holes can be used for flange-mounting.
Monitoring elements
A difference pressure switch monitors the pressure drop in the duct accommodating the heating grids. If the fan fails or if the flow of air is throttled inadmissibly, the unit is switched off by the master contactor.
Additional monitoring elements serve to guard against damage by overload for
the Resistive load unit,
the Inductive load unit,
the A.C. power unit.
In case of excess voltage or over-current an electronic excess voltage resp. over-current release responds, the unit is switched off by the master contactor.
PTL Power Supplies for higher test currents on request
PTL Fluorescent Lamp Equivalent Accessories on request
PTL Actuating Units for switches and socket outlets see F 55.10 and F 55.30
Click here for prospectus as PDF 
N03033e009 2010-05-07 2010 PTL Dr. Grabenhorst GmbH, Stadtsteinach, GERMANY