10 HDB Electricity Loading Tips
You may know that electric works are a key component of a home renovation, but do you know exactly what to look out for when engaging in electric works for HDB flats?
By Hilary Fong -
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What is HDB electrical loading?
HDB electrical loading refers to the maximum capacity of electrical power that a HDB flat can consume without overloading the circuit. The electrical wiring, switches and appliances installed in the flat are factors that will affect the total electrical loading.
HDB flats built before January 1994 are equipped with 20A main switches, while the later flats typically have 40A main switches. However, HDB has been expanding upgrading works for the older HDBs by installing new infrastructure to increase the electrical loading.
How to check my HDB electrical loading?
If you have purchased a resale flat that was built before 1994 and unsure if the loading capacity has been upgraded, you may check on the HDB website by keying in your postal code here.
Why is it important to know the HDB electrical loading?
Understanding the HDB electrical load is essential in ensuring that your home is safe from hazards and power disruptions. If your electrical loading is high, it leads to higher bills and higher risks of power trips. An overloaded electric system can also cause your appliances to malfunction and in serious cases, cause electrical fires.
HDB also has various guidelines for electrical installations and failure to comply may result in fines or even imprisonment. All electrical installations must be approved by HDB before execution.
10 HDB electrical loading tips
1. Check your electrical load capacity
Older HDB flats that were built before 1994 usually have a 40A main circuit breaker, while the newer flats have a 60A main circuit breaker. It is important to understand the electrical loading capacity of your flat as exceeding the limit can cause power trips or lead to fire hazards.
You may check the electrical load capacity by looking at your HDB’s main electrical distribution board, also known as DB box. It is typically installed on the wall near the main door. The main circuit breaker should indicate 40A, 60A or 80A.
If your main circuit breaker is only 40A, you should ensure that you have minimal heavy power appliances and the total power of your appliances falls below the load capacity. If your electrical demand is higher, an electrical load upgrade may be necessary.
2. Upgrade the main switch to 40A
A 40A switch is essential for regulating high power appliances such as air conditioner, water heater, induction cooker and built-in oven. When an appliance takes up more than 40A, the switch trips, preventing the wires from overheating and fire hazards. If you’re installing heavy appliances, you should ensure that the switches are upgraded to 40A to meet safety standards.
3. Choose the right pole design of switches
The pole design of a switch refers to how many circuits it can control. Selecting the right pole configuration ensures safety and efficiency.
Single-Pole (SP): controls one circuit, typically used for small appliances (eg. lamps, fans).
Double-Pole (DP): controls two circuits, typically used for heavy appliances (eg. water heaters, ovens, air conditioners).
When choosing the pole design, you should ensure that the switch matches the appliance’s voltage and current rating. You should never replace a double-pole switch with a single-pole switch for high power appliances.
4. Engage an EMA-Licensed electrician
According to HDB guidelines, all wiring installation works must be done by a Energy Market Authority (EMA) licensed contractor. You are also required to submit the SP Services Ltd (SPSL) Form CS/5H endorsed by HDB to SPSL for testing of any new electrical wiring or extension work.
If you need to upgrade your switch to 40A, you should speak to an EMA licensed contractor and submit an application for a permit. Any unauthorized work can cause electrical hazards and void HDB insurance coverage.
5. Manage air conditioner installation properly
All air conditioners have to be installed by licensed contractors trained by the Building and Construction Authority (BCA). Different HDB types (eg. 1-room, 3-room, 4-room) also have different limits for the maximum running current and maximum weight allowed for condensing units. It is important to take note of the guidelines and ensure that you apply for the necessary permits before installation.
6. Plan your usage of kitchen and heavy appliances
Appliances like air conditioners, refrigerators, washing machines, induction cookers and ovens consume the highest amount of electricity. When operated at the same time, there is a higher risk of overloading the electrical system, leading to power trips. In order to prevent overloading, avoid running multiple appliances at the same time.
7. Manage water heater power load
In 2023, CNA published an article about things you should know about your water heater to prevent deadly accidents, citing some cases of fire, electrocutions and explosions that have happened in Singaporean homes due to mismanagement of water heaters.
In general, there are two types of water heaters - instant and storage water heaters. Instant water heaters draw more power than storage heaters as they supply hot water instantly through a heating element powered by electricity. Unlike instant water heaters which heat water on demand, storage water heaters preheat the water using an electric heating coil inside the tank, and store it for later use.
Storage water heaters have lower electrical demand than instant water heaters. Hence, if your home is equipped with instant heaters, do not use them simultaneously with high power devices like the dishwasher or oven.
8. Use surge-protected multi-plug adapters
You should opt for high quality, surge-protected adaptors to ensure safety and lower risks of hazards. Surge-protected adaptors are designed to absorb and divert excess voltage away from connected appliances, preventing damage caused by sudden spikes in electricity.
You should also avoid plugging multiple adaptors into each other or connecting multiple extension cords with each other. The total power load on the adaptor should not exceed the stated capacity.
9. Balance your power usage
High power appliances should have dedicated power points and circuits to prevent overloading. Major appliances such as refrigerators and ovens should be separated across different sockets instead of using extension cords. Heavy appliances should not be operated at the same time to prevent overloading.
10. Schedule regular electrical inspections
To ensure that your home electricity is running properly, you may engage an EMA-licensed electrician to conduct checks on your wiring every 3-4 years. If you experience frequent power trips or notice abnormalities such as loose sockets, flickering lights or burning smells, you should engage a professional to investigate and resolve the issue.