Temperature rise test panel for domestic switch
Specifications
Input supply : 230v ac + / - 10% , 50 hz single phase with mcb protection.
Output : current source 0 to 50 a max
Digital voltmeter : 3-1/2 digit 0 to 300v
Voltage drop indicator with range selector.
Digital temperature indicator with 12 channels.
Current controller for maintaining the output current at pre-set value.
Ct range selector for accurate measurements.
Description
The test panel is made to suit the specification as mentioned in is : 3854 of 1997 for temperature rise test.
The test panel broadly comprises of :
1. Ac constant current source ( true rms ) for 50 amps max / 5v.
2. Universal servo controller, for controlling the output current with the help of motorised variac
Assembly.
3. Digital ac voltmeter to read the primary voltage of the power transformer. It helps to eliminate the
Possibility of hunting of motor with the help of primary tap selector switch.
4. Digital temperature indicator controller - 12 channels - with thermocouples, to read the temperature rise
At different parts of the switches.
5. Digital ac voltmeter with terminals and three ranges - 0.2, 2.0 & 20 v to measure the voltage drop
Across the switch terminals while passing the specific current.
6. Range selector switch for ct to measure more accurately the current for lower as well as higher range.
7. Push buttons for test on / off with output indicating lamps.
8. Mains on mcb 2p / 10 a.
SCR Electroniks make, Shutter Socket Test Apparatus is designed to carry out Socket Shutter Test¦. The apparatus is designed & manufactured exactly as per the IEC & IS Specifications
Test Apparatus consists of following parts :
1) Motor to achieve 20 cycles / minutes speed D.C. Motor of suitable is used.
2) Mechanical Assembly : Consists of following parts :
Test Plate & Test Plate Mounting Block : On Test Plate socket under test is mounted. Test Plate is in turn mounted on two Mounting Plates with provision for lateral position adjustment. to take care pf different thickness sockets. Provision is made for adjustment along X axis & Y axis, so that µTest Plug Pins¦ engage exactly in to the holes on the µSocket Under Test¦. This is stationary during test.
Test Plug with mounting arrangement (moving) : Test Plug is made as per Cl. No. 24.10 fig. No. 25 and mounted on moving block.
Movement Transfer Arrangement : Consists of (a) Circular Disc, with offset link (b) Lateral Link, connection between offset link and µTest Plug Moving Block¦.
Control Unit.
Electronic control unit is with following Controls & Indications.
Name Type Function
Power ON Switch Rocker Switch (Teknic) Puts the Apparatus ON / OFF.
Power ON Indicator Neon v Built v In Indicates Power ON / OFF
Counter + Reset Button 6 digit Gujral Make Counts no of cycles.
Hold Time Set v 2 digit. Thumb Wheel Switch To set hold time between (1-99 sec).
Micro Switch is provided to sense µLimit Position¦ of moving block in forward direction, which triggers the µHold Time Counter¦. After preset time µHold Time Counter¦ resets, and motor starts to actuate backward movement of moving block.
Battery Backup :
In case mains power goes off, in course of testing, the count is retained, and when mains power resumes the dimmer under test is restored to Off position i.e. Home Position, without this incomplete operation getting counted, and then operation starts normally.
To reset count to Zero : Put On the µPower ON Switch¦, while µReset Button is being pushed.
Glow wire tester
Discussion of the Glow Wire Test (Varies as per relevant standard):
1. Object of the Test -
Components or parts under Fault or Overload conditions, may
attain a Temperature such that they will ignite parts in
their vicinity.
The GLOW - WIRE Test simulates thermal stresses which may be
produced by such source of heat or ignition. e.g. glowing
elements or overloaded resistors, may be for short duration,
in order to assess by a simulation technique the Fire Hazard.
2. General Description of the Test -
a. If possible, the specimen should be a complete
equipment, sub-assembly or a component.
b. While taking a part / parts of an enclosure for the
Tests, care must be taken to ensure that the Test
Conditions are not significantly different from those
occurring in the Normal usage, with regard to shape,
ventilation, effect of thermal stress and possible
flames occurring, burning or glowing particles falling
in the vicinity of the specimen.
c. The Test is applied to ensure -
1. That the Glow - wire Loop which is electrically
heated to a temperature specified, does not under
defined conditions cause ignition of the Part/Parts.
2. That the part which might have been ignited, has a
limited duration of burning, without spreading of
fire by its flame or burning or glowing particles.
d. This type of test may not be appropriate for too small
components / parts / sub assemblies, which may need
Needle Flame Test.
3. Test Apparatus -
a. The Glow - Wire consists of a specified loop of a Nickel
/ Chromium ( 80/20 ) wire of 4 mm dia.
b. Sheathed fine wire thermocouple, of overall dia. 0.5 mm
( wires of NiCr & NiAl ) with welded point / joint
located in the 0.6 mm hole in the Loop of Glow - Wire.
c. The Sheath consists of metal , resistant to a
temperature of 960 deg. C in working.
d. The instrument for measuring thermovoltage have 1 %
accuracy.
e. The Test Apparatus is so designed that the Glow - Wire
Loop is horizontal and the mounted specimen moves
horizontally towards the Loop with a force applied 0.8
to 1.2 N, for a penetration distance of 7 mm max.
f. To evaluate the possibility of spread of fire, a layer
of the material or components normally surrounded
underneath the specimen is placed underneath the
specimen at a distance equal to the distance between the
specimen and the surrounding material or components when
the specimen is mounted as in normal use.
If a subassembly or a part of the equipment is tested
separately, a piece of white pinewood board,
approximately 10 mm thick and covered with a single
layer of tissue paper, is positioned at a distance of
200+/- 5mm below the place where the glow-wire is
applied to the specimen, unless otherwise specified in the relevant specification.
