A BRIEF WRITE-UP ON QM AND CONTROL POLICIES & PROCEDURES ADOPTED AT PRITHVI TECHNOLOGIES PVT. LTD, THANE
The `ELECTROMIZER’ is a proprietary equipment and is sold in the market in the form of a panel complete with switchgear. While the basic equipment is the REACTANCE COIL, all other items are subcontracted or bought out. Assembly however is carried out at our own premises.
We have defined Quality assurance procedures in various stages of `ELECTROMIZER’ manufacturing activity. A brief item & process wise synopsis is given below.
The entire product can be split up in three parts as under:
1. `ELECTROMIZER’ reactance coils.
2. Panel enclosure
3. Switchgear items
1. The reactance coils are manufactured at the plant of our Associates M/s. Gilbert and Maxwell Pvt Ltd., Nashik. While the main inputs to the coil are enameled copper wire and CRGO core, other items like nuts-bolts, epoxy, insulation paper material, terminals etc are also used.
a) SUPER ENAMELLED COPPER WIRE - Electrolytic grade - meeting IS-13730 is used. The wire meets Class
'F' requirements of insulation (155 degrees C). The design temperature rise of the assembled coils is within Class
b) Core : Made out of Prime imported CRGO (Cold Rolled Grain Oriented) material meeting M4 or better specs. This is tested prior to use in `ELECTROMIZER’ for guaranteed B-H curve and other parameters as per test certificate issued by the manufacturer. Tests are carried out to confirm that the B-H curve does not saturate over the entire design range of operation. The basic CRGO material is sourced from Japan or European countries like Spain, Italy or sometimes even USA. To the best of our knowledge, there is no known IS for CRGO material.
The CRGO material used in the `ELECTROMIZER’ reactance coils has a guaranteed loss of less than 0.9 Watts per Kg.
c) Terminals and other hardware used is made out of extruded Ni plated brass. At the same time, tin plated electrolytic grade copper bus bars are used where current requirements demand
d) Insulation material of highest grade and appropriate thermal grade is used
e) Epoxy resin of reputed make - CIBA (VANTICO) or ATUL Ltd make is used.
The `ELECTROMIZER’ coils are rated for continuous operation at 100% load, approx. 6
hours for 110 % load, 30 minutes for 120% load and ALSO indefinitely for upto 115% over voltage.
The finally assembled coils are also subjected to routine tests as under:
A) Physical / Mechanical Tests :
1) Looks - Neat & Clean
2) Firmness of terminal strips, terminals, Holding bolts
3) Connections - Marking & Position
4) Labelling - Rating plate data shall be legible as specified
5) Overall dimension - As per customer's specs or our standard drawings
B) Electrical Tests :
01) Megger Test
03) Polarity Test
04) Resistance Test
05) Inter turn Test
06) Ratio Test
07) Accuracy Test
08) OC & SC test
09) Heat run test (By using short circuit method)
13) Knee point Voltage test
2. PANEL :
Prior to taking up the panel for fabrication, a GA drawing showing details of construction and the BOM of switchgear used is sent to the client for approval. Details of dimensions, cable entries, cable glands, terminations, locations of meters, phase indicating LEDs, SFUs, etc have to be Okayed by the end user after considering his specific requirements as well as site conditions. On receipt of the original APPROVED drawing and BOM, the panel is released for fabrication.
The panel is fabricated out of CRCA sheet SWG 18 / 16 /14 as specified in the approved GA drawing & depending on various factors like the size of the panel, whether the panel is to be placed indoors or outdoors etc.. At the same time, the doors and frames are made out of CRCA sheets of suitable SWG size.
Prior to the start of activity of fabrication, the steel sheets are inspected for quality and thickness. Subsequently, when the panel is ready for powder coating, the entire structure is checked for surface evenness, dents, sharpness of corners, doors and walls alignment, welding of joints, brazing, etc. At the same time, the panel is checked for dimensional conformance with the approved GA drawing. All panels are treated by Seven-Tank process prior to powder coating.
The fabricated panel then is sent for powder coating. Random checks are carried out at the powder coating facility to check conformance of process with specified norms like thickness of coat, temperature of oven, time duration of oven baking, colour shade (e.g. Siemens Grey - 631 etc.). On completion of process, the panel is inspected for evenness of powder coat, thickness (checked randomly at different points on the panel). The panel is then cleared for assembly.
3. SWITCHGEAR & CABLES / BUSBARS / CONNECTORS :
All incoming switchgear and cables / connectors and other hardware is checked for make / manufacturer, model & ratings conformance with order specifications. At the same time, each Contactor, MCB, MCCB, SFU, Timer, Voltage Relay is checked for operational performance. Any faulty material found is recorded and returned to the supplier for replacement. Bus bars & Cables as well as other hardware too are checked for quantity, make and size / specifications. After the incoming check, the OK materials are stored separately for use later.
At the time of assembly, all necessary switchgear materials are issued from the OK lot and tested once again PRIOR TO FITTING in the panel.
The panels assembly will generally meet all relevant standards as specified in IS as specified for LT applications. This includes gasketing, cabling, ferruling, lugging, channeling, terminating, spacing, shrouding, labeling etc. as specified in the relevant IS.
On completion of assembly, the panel is once again tested for operational correctness as also for insulation resistance (HV and Megger tests). Correctness of input and output voltages is checked and recorded.
A final test certificate is issued (original to customer & copy for our records) certifying operational worthiness of the `ELECTROMIZER’.
Packing of panel is done in plastic sheet & gunny sack cloth with all meters and other damageable items well protected with thermocole sheets. Such packed panels are then placed further in wooden crate containers tailor made for each panel. All packing is done with a view to avoid transit damage.