Electrical System Design

Posted by Safety Acts | 8:03 PM | | 1 comments »

" Faulty Electrical Wiring", the most common findings of fire investigation department during fire. It's unfair for all electrical practitioners. For an efficient electrical system, brainstorming, effective planning and implementation is important.

Electric Power has a wide range of application. The world can't live without electricity. It is important in any industries from manufacturing, transportation, communication and down to the household. For large scale manufacturing, it is a must for the designer to plan and execute the reliable system without affecting the process. Any failure of the system will stop the process. Among the most common causes of  power outages are the constant tripping of the of protective devices, premature breakdown of equipment, power harmonics, low power factor, high voltage drop, low short circuit MVA from utility company, improper sizing of protective devices and conductors, and improper settings of relays and circuit breakers.

An electrical designer must come up with a reliable and economical system. It starts with the single line diagram which shows the whole electrical configuration from the service drop of the utility company, service entrance, High Voltage Switchgear, Low Voltage Switchgear, Transformers, Circuit Breakers, and distribution panel boards.

These are some key factors to be considered in designing power system:

1. SAFETY- this is always the first and important factor. Enclose all exposed conductors. All protective devices must have proper interrupting capacity to withstand high flow of short circuit currents. The conductors must have enough ampacity, the logic is that, it must have higher ampacity than the current rating of the circuit breaker. The circuit breaker must be able to cut the power during short circuits before the conductors and equipments are damage.
2. ECONOMICAL- this is another important factor though contradicts safety and reliability. It must not be evaluated on per equipment basis, rather, it must be evaluated as a whole especially in computing the return of investments.
3. EXPANDABILITY- anticipate the growth of the company. Provide an extra power capacity to allow additional installation. It is imortant to reserve in substation KVA size over predicted present loads, margin in interrupting rating of switching devices and proper selection of voltage level.
4. SIMPLICITY- the design must be as simple as posible. Most shutdowns are associated with the complexity of electrical system especially during preventive maintenance and repairs.
5. FLEXIBLITY- the electrical system must be capable of being expanded without requiring major changes in the power distribution. The use of load center type system with small substations that can be added in small units is one basic consideration in plant flexibility.
6. RELIABILITY- it is directly proportional to productivity. The designer can consider radial system, loop system, or double-ended-system  configuration and install high quality electric equipment and excellent workmanship.
7. SELECTION OF EQUIPMENT- Install equipment with adequate voltage level, current level, interrupting rating, and proper protection.
8. MAINTENANCE- design a system that will provide alternate supply to permit to be taken out during preventive maintenance without affecting the critical loads.

A Quick Guide After Earthquake

Posted by Safety Acts | 2:09 AM | | 0 comments »

Right after the shaking, stay at your place for some moment. Observe the surroundings for the posible after shocks and prepare where you will cover when it occurs. Here are the things you can do:

1. Check for casualties and injuries. If posible, give first aid
2. Remain calm and motivate others to stay calm , have courage to move on.
3. Avoid broken glass, doors, cabinets, and debris.
4. Check for fire, electrical sparks and gas leaks
5. Shut off the gas leaks, power supply and water
6. Use transistor radios to know the current and updated news.
7. Stay out of the damaged building.

EARTHQUAKE PREPAREDNESS

Posted by Safety Acts | 10:10 PM | | 0 comments »

For the past few weeks, earthquake is unpredictibly hitting in different part of the world leaving too much destruction and caused thousands of lives. To date, there is no invented modern device to predict when it will happen and the exact location unlike the tropical storm where signals can be given depending upon the location and speed of wind. Recently hit by strong earthquake were Haiti, Chile, and Taiwan. In deed, it caused to much damage to properties. Since we can never know when it will happen, emergency preparedness readiness must become a way of life. Be ready with necessary suplies such as food, medicine and other basic needs since the quality of life and potential for survival are greatly increased by being prepared. What to do during earthquake?

 INSIDE HIGH RISE BUILDING:

DUCK, COVER, AND HOLD. Duck under sturdy/hard table. Stay away from windows, bookshelves, mirrors, hanging objects that could fall. Watch out for falling ceiling or tiles. Stay covered until the shaking stops. Hold on to your cover. If you are not near dest or table, move away from interior walls. Protect your head with your arms. Do not use elevators.

IF YOU ARE OUTDOORS

Move to clear areas away from trees, signages, buildings, electrical wires and poles.

@ SIDEWALK NEAR BUILDING

Duck into the doorway to protect your head from falling debris, glass, plaster and bricks.

DURING DRIVING
Pull over to the side of the road and stop. Avoid overpassess, powerlines and other hazards. Stay inside the vehicle until the shaking is over.

@ WHEELCHAIR
Stay sitted on it. Move to cover, the lock your wheelchair. Protect your head with your arms.

LPG SAFETY TIPS

Posted by Safety Acts | 11:27 PM | | 1 comments »

Liquified Petroleum Gas ( LPG ) is a mixture of 60% butane and 40% propane. It is widely used in homes, industrial processes, restaurants, and even in auto industry as source of fuel. For home use, it is commonly sold in 11 kg , to check if it is correct, weigh the filled up cylinder then subtract the indicated tare weight of the container. The Difference must be equal to 11 kgs.

Here are some safety tips for using LPG:
1. Check rubber tubes/hose for cracks and holes. It is recommended to replace at least every two years.
2. Retain safety cap with nylon thread attached to cylinder. Fix the cap on the valve to stop the leak if any.
3. Do not place the cylinder in a closed compartment and keep the stove in the platform or table above the cylinder level.
4. Check for leaks by applying soap solution at the cylinder valve , joints , hose
5. Always keep the cylinder in vertical position with valve on top and installed at ground level.
6. Cylinders must not installed near heat sources, sunlight, rain, dust and heat.
7. For large containers always provide hoist and support
8. Do not place the cylinder near electrical outlets and switches to avoid electrical sparks.
9. Install gas detector at the kitchen
10. Provide fire extinguisher

In case of leakage, Do not panic:

1. Open all windows and doors
2. Switch off the regulator
3. If leakage is from the valve, immediately put the safty cap
4. Take the cylinder in an open space and contact the distributor
5. Don't switch on any electrical device in your house.
6. Don't light matches nor cigarettes

INDUSTRIAL SAFETY CHECKLIST 2

Posted by Safety Acts | 10:59 PM | | 0 comments »

@ PRODUCTION AREA

1. Circuit disconnects must have proper covers, enclosures and fastened
2. No flexible cords taped and exposed wires
3. Emergency devices and sensors are properly working
4. Indicator lights are working
5. Switches and circuit breakers are labeled
6. All seal are tight and properly fitted
7. Electrical cords/ power supply do not hang on walls
8. Electrical panel board are accessible

@ ELECTRICAL ROOM

1. Floors must be always dry
2. Proper warning signs " HIGH VOLTAGE" posted
3. Do not use as storage area
4. Restricted to unauthorized users
5. Emergency light must work up to at least 2 hours without normal power
6. Proper ventilation of equipments
7. Single line diagram posted

INDUSTRIAL SAFETY CHECKLIST 1

Posted by Safety Acts | 11:43 PM | | 0 comments »

Here are the practical recommended checklists to maintain safety:

1. All power room and electrical room must be kept  clean and accessible at all times
2. No combustible  materials near the electrical conductors, panel boardsm switchgear room and electrical rooms.
3. All electrical panel boards must be accessible and free from obstructions.
4. There must be installed emergency lights, exit lights, evacuation route plan located at strategic locations.
5. Always observe lock-out-tag-out during repair,maintenance and temporary installations.
6. Proper identification of phase and phase sequence of terminals at panel boards are properly identified to avoid reversal of motor rotation and balancing of single phase loads.
7. Using of extesion cords must be for temporary only . It's load must not exceed 180 W. Avoid too much interconnection of  extension cords.
8. All conductors/wire must have proper conduit to protect them from physical damages.
9. Properly support the lighting fixture and proper illumination for particular type of activity
10. Always return dead front cover of panel board and provide proper circuit directories.

MY SAFETY CHECKLIST

Posted by Safety Acts | 11:45 PM | 0 comments »

1. Use EXTENSION CORDS for temporary basis only. Avoid interconnecting too much extension cords without checking the capacity of its main protection. Its capacity is only up to 180 W per outlet.

2. Replace or put covers on dilapidated switches, receptacles and extension cords
3. Switch off the main breaker or fuse when there is spark, odor, smoke coming out from the receptacle and outlets.

4. Unplug appliances when leaving or not in use
5.Do not touch exposed wires and terminals
6.Cover receptacles when there is a baby playing around
7. Orient your children for the hazard of electricity
8. Do not touch television or CRT monitors of computers with wet hands or in bare foot
9. Consult electrician before addidional loads.
10. Have your electrical connections checked by a qualified electrical parctitioner.

"Faulty electrical wiring comes from unsafe practices"

HOW TO USE FIRE EXTINGUISHER

Posted by Safety Acts | 11:15 PM | | 0 comments »

Using fire extinguisher is very important. It will be useless if the user don't know how to activate the extinguisher. Only one word to remember: P-A-S-S

Once You have the fire Extinguisher, just the following simple and effective steps:

1. Keep your back to a clear escape route.

2. Stand 6 to 8 feet in front of the fire
3. Do the  P-A-S-S

P-ULL THE PIN

A-AIM at the low base of Fire



S-QUEEZE the lever

S-WEEP side to side




Watch the fire area and assess the situation. If it flares up, then leave the place immediately and call the fire department. It is very much important to know the nearest emergency exit.

Here are the basic types of Fire Extinguishers to be used for each particular fires:

1. TYPE A OR WATER 

          Combination of water and Carbon Dioxide propellant. This can be used for type Class A fires  such  as wood, paper, plastic. Do not use this on Class C fire specially when there is live wires to prevent electric shocks.

2. TYPE ABC OR DRY CHEMICAL
           Use in Class B fire. Best for general use. It reduces re-ignition during fires. The Carbondioxide-BC rated is best for burning liquids and electrical fires.






3. TYPE CARBONDIOXIDE AND HALON
          The Halon-BC rated is best for computers and electronics.





These types of fire extinguishers will guide us in supprresion of the specific fire. Prevention is always better than suppression. Safety acts will always make way to safe and worry free living.

          It very important to know the type of fire is present for it to be extinguised properly and immediatley. Here are the classifications of fire based on the Fire Code of the Philippines:

1. CLASS A FIRE - it involves ordinary combustible materials such as wood, cloth, rubber and plastic.

      

         This type of fire can be extinguised by cooling or using as water to remove the heat and stop the fire

2. CLASS B FIRE - involves flammable liquids, oil, gasoline, solvents and gases.


 
          Can be extinguised by blanketing the fuel thereby interrupting the chemical process at the fuel surface.

3. CLASS C FIRE - involves energized electrical equipments, computers, and electronic devices.



         
            It can be suppressed by smothering the fire or displacing the oxygen.

4. CLASS D FIRE - involves combustible materials, such as sodium, magnesium, potassium and other similar products.

5. CLASS K FIRE - in cooking appliances that involve combustible cooking media ( vegetable, oil, fats)


           These types of fire will determine what type of extinguishing equipment will be used to further stop the fire right away  and not create any further damage for using not suited type of fire extinguisher or fire suppression system.

The three elements of fire are fuel, heat, and oxygen. All of these elements must be present before it will thrive and spread out. Without any of these elements, for sure, fire will not materialize.




 1. FUEL
        Any kind of combustible material (wood, clothing, paper, chemical) characterized by its moisture content, size, shape, and its arrangement.
        Once the fuel is removed, the fire will starve and be easily extinguished.

2. OXYGEN
        Our atmosphere contains 21% oxygen. Most fire require only  16 % oxygen for the oxidation process to occur. When fuel burns, it reacts with oxygen from the surrounding atmosphere releasing heat and generating combustion products.
        When oxygen is removed,  the fire will be suffocated and out.

3. HEAT
       This is responsible for the ignition of fire. It is needed to maintain the fire and spread it out by removing the moisture from fuel, warming the surrounding air, preheating the fuel path enabling it to travel fast.
        Removal of heat is the most common type of suppression. In most cases, water is used to soak up heat generated by fire.


        The interaction of each side of the fire triangle is required for the creation of fire. When not enough heat is generated, not enough fuel is available, and no oxygen is present, then no fire will be created. Fire can be prevented when each elements is  properly isolated.          
        No one knows when fire will happen, yet it can be prevented by not allowing the three elements react with each other. Proper housekeeping is very important.