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.


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?


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.


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


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

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.

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


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


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


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


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


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.


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"