End of Line Testing – Case Studies

Motor Test System

MELSS has developed and deployed Motor Test System, where an AC induction motor is used as a load instead of a dynamometer. These testers are used in product qualification and analysis of motors and related electronic systems.

The motor test system is connected to the gear system, which in turn is coupled to the AC induction motor which acts as the load. The instrumentation and control system is housed in a 19″ rack.

Parameters:

  • Voltage
  • Current
  • Power
  • RPM
  • Noise
  • THD
  • Efficiency
  • Torque

Hardware/Configuration:

  • Power supply
  • Gear box
  • AC motor
  • Noise sensors
  • Power meter
  • VFD
  • RPM sensors
  • Holding assemblies
  • IPC/PXI system
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Thickness Measurement System

MELSS offers Thickness & Dimension Measurement Systems. While there are many contact and non-contact technologies available, laser sensor based triangulation was selected for its high resolution, accuracy, linearity and frequency response. In addition, they are relatively less affected by temperature, acoustics etc. Some of the features of the system are:

  • Three point measurement
  • Synchronised lasers
  • Positional movement of laser sensor using VFD
  • PLC control system
  • High speed data acquisition
  • Reference jig for calibration
  • Micron or mm level variation
  • Test component in various speed motion/rotation
  • Suitable for use by semi-skilled operators
  • Online data logging
  • Access control software
  • Discreet testing
  • Feedback available from the tester to the system for online modification
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End of Line Testing

Leakage Test System

It is critical to test components that operate in a sealed pathway for any leakage in the junctions. MELSS designs and supplies systems to verify if the components have any leakage – micro or observable.

Air is let in to the component at a pressure which is marginally higher than the regular operation pressure. Once the volume of air has reached the required level, the flow is stopped, and the pressure is monitored for a fixed duration. If there are any micro cracks or major leaks, the pressure will gradually/drastically reduce as per the case. This pressure is read through the pressure meter.

There are two variants to this system – without data logging or with data logging and controller. There are number of pressure variants.

These systems are built to meet strict safety standards (CE/UL) and IEC specifications.

Some of the features/specifications are:

  • Pressure range: 0 to 200 psi
  • Size of component inlet: 1/4″ to 10″
  • Enclosure: MS with powder coating/polycarbonate
  • Display: Analogue/Digital
  • PLC Control System: Optional
  • Reports: Optional
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Robotic Gluing and Ball Assemble Machine for Dual Bellow 

Client: private company

Industry: Fluid control equipment, pump, seal, valve manufacturing, climate & energy.

Client Requirement: Gluing and Ball Assemble Machine for Dual Bellow.

Challenges:

  • A robotic solution for assembly operation.
  • A device to improve working efficiency.
  • The equipment to measure the dimension.
  • A device to control motion, that is efficient and maintenance free.
  • The level of air that is required for object handling tasks.
  • A device to dispense glue.
  • A device to measure the pressure.
  • Custom designed pneumatically operated control gates.

Solutions: 

  • SCARA Robot is implemented for operation.
  • Sixdime NFC reader is used for part tracking.
  • LVDT is used to measure the bellow height.
  • Linear Actuator is used to control the motion, that is efficient and maintenance free.
  • The vacuum is generated using a vacuum Pump up to Vacuum level <2.2 mbar.
  • The glue dispensing syringe will dispense the glue on the ball press area.
  • Vacuum Pressure gauge is used to measure the pressure.
  • HMI is used to control the machine.

Over view:

Melss offers successful End of line test system over the years, Vacuum sealing and test system is one of the robotic solutions for end of line tester. It’s a fully automated robotic solution. Basically, this system is used for vacuum generation, dimensional measurement and adhesive application. The solution also has an automated storage rack to load all units at once and it’s having RFID traceability so it does the job faster than usual. The curing stacker is also available to allow for adhesive curing before it is retested and classified as pass or fail.

Customer Benefits: Robot has been delivered to reduce the Process cycle time, achieve better productivity and also reduces the human fatigue.

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End-of-Line Tester for Pressure Switch

Client: International private company

Year of Installation: 2020

Client requirement: Supply of Electrical test panel for pressure switch.

Industry: Fluid control equipment, pump, seal, valve manufacturing, climate & energy

Challenges:

  • Solution to check the exact pressure of the switch.
  • Tank to supply pressurized air.
  • To test the pressure switches by applying the various load parameters.
  • To control the whole testing system.
  • A coil to allow the pressure in to the system.
  • To convert pressure into an electrical signal.
  • To sense the current through the pressure switch.
  • To control the high load current conditions during the test.
  • To accessing the logged data and monitors the statistics of data.

Solution:

  • A test panel is implemented to check the exact pressure of the switch.
  • The pressure reservoir tank is initially used for supplying the pressurized air to the pressure switches in the test panels.
  • The load bank is installed to test the pressure switches by applying the various load parameters through contactor switching.
  • A siemens PLC CPU 1215c is mounted in the main panel for controlling the whole testing system.
  • The solenoid coil is used to allow the pressure into the system after getting the PLC command.
  • The LEM current transducer is used to sense the current through the pressure switch by connecting across the pressure switch.
  • The thyristor module is implemented for controlling the high load current conditions during the test.
  • The touch screen monitor is used for accessing the logged data and monitors the statistics of data.
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Over View:

MELSS offers successful End of line test system (EOL) over the years, to test pressure switch we supplied Electrical Testing Panel. There are three test panel implemented  AC1, AC3, AC15/DC13.The AC1 test panel is placed on the left-hand side of the entire panel assembly set up. It consists of interface modules connected to the CPU module in the main panel through Ethernet. The AC3 test panel is placed next to AC1 panel of the entire panel assembly set up. The AC15 test panel is placed next to main panel of the entire panel assembly set up. The counters for each pressure switch are mounted on the front of panel for the count of number of cycles tested. The pressure switches in this panel are tested by connecting the inductive/DC coil loads to the pressure switch by a corresponding contactor .A thyristor module SKKT 162/12E inside the panel is connected between the contactor and load bank for controlling high load current during the test.  The pressure reservoir tank is initially used for supplying the pressurized air to the pressure switches in the test panels. The pressure inside the tank is maintained by the feedback from the pressure transmitter for switching the solenoid valve to generate the pressure up to the set value. The load bank is used for the testing of the pressure switches by applying the various load parameters through contactor switching. An oil immersed load bank consists of a heat exchanger in which the hot oil flows through the pipelines for the cooling of oil by forced air from a fan fixed aside on it. The oil temperature in the load bank tank will be sensed with the help of two RTD sensors feedback signal and can be controlled by operating the oil pump to flow the oil to the heat exchanger. Resistive loads are used in AC1 and AC3 panel; Inductive loads are used in AC3 and AC15 panel; DC coil loads are used in AC15 panel. A siemens PLC CPU 1215c is mounted in the main panel for controlling the whole testing system. The three interface modules IM 155-6 is used in the AC1, AC3 and AC15 panels with the IO module for connecting the input and output devices.  An Ethernet switch is used in each of these panels for connecting all the interface modules with the CPU. The solenoid coil is used to allow the pressure into the system after getting the PLC command. In a test panel there will be a 3 no’s of solenoid coil for each of the pressure switch under test. So, in a test panel there will be a 5 no’s of pressure switch for which this process repeats in a sequence to complete single test cycle. For a test a total of 1 lakh such cycles should be completed. The pressure transmitter is fixed at the outlet of the pressure storage tank. This maintains the pressure up to the set value and gives the feedback to PLC for the ON/OFF command of solenoid valve at inlet. The LEM current transducer is used to sense the current through the pressure switch by connecting across the pressure switch. The input to the current transducer is from the SMPS 1A +15V/-15V and the output from the current transducer will be +/-4V for logging of pressure data by supplying to the NI (National Instruments) card. These thyristor modules will be connected between the load contactors and the pressure switches.  For the transfer of excess heat from the module during operation an aluminum heat sink is provided as base on which the mounting is done inside the panel.

Customer Benefits:

We have reduced down time, increase safety, save money and improve system performance.