Many people wonder if it is safe to plug one surge protector into another, essentially “daisy chaining” them together. The short answer is no, it is not recommended to plug a surge protector into another surge protector. However, there are some nuances to this issue that deserve a more in-depth look.
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What is a Surge Protector?
A surge protector, also called a surge suppressor, is an electrical device designed to protect equipment from power surges and spikes. Surge protectors monitor the flow of electricity and prevent or “suppress” sudden spikes in voltage from reaching connected devices.
Some key features of surge protectors include:
- Safety shutters that prevent electricity from flowing when the protector is not plugged in
- Internal components like MOVs (metal oxide varistors) that divert excess energy
- Joule rating indicating the maximum amount of energy it can absorb
- Clamping voltage threshold that triggers the protection
- Surge protection indicator lights that notify users if protection components are no longer functioning
- Multiple outlets allowing connection of various devices
By absorbing or blocking power surges, surge protectors help prevent damage to sensitive electronics like computers, TVs, gaming systems and kitchen appliances.
Why You Should Not Plug a Surge Protector into Another Surge Protector
There are a few key reasons why daisy chaining surge protectors is not recommended:
Overload and Fire Risk
Plugging one surge protector into another can overload the electrical circuit and result in overheating or even fire. Most surge protectors are designed to handle a limited amount of power flow. Piggybacking them increases the chances of exceeding the recommended wattage rating. This could cause the protectors to generate excessive heat that could melt plastics and start an electrical fire.
Reduced Protection
Using surge protectors in series dilutes the protection provided to connected devices. For example, if you daisy chain three surge protectors that are rated at 400 joules each, you do not get 1200 joules of protection. In reality, the overall protection will be significantly less than 400 joules.
Safety Features Bypassed
Surge protectors have built-in safety features like circuit breakers and fuses that get bypassed when they are daisy chained. This eliminates an important layer of protection against electrical faults.
Manufacturer Warnings
Most surge protector manufacturers state in their manuals that you should not plug their devices into other protectors. Doing so voids any warranty and UL safety certification. This is because they are not designed to handle the electrical load of multiple units.
Are There Any Exceptions?
While daisy chaining surge protectors is generally not recommended, there are some exceptions where it may be considered safe:
Using a surge protector power strip as an extension cord
It is generally okay to plug a basic power strip without surge protection features into a surge protector as an extension cord. This can provide additional outlet capacity without the risks of overload that come from chaining two surge protectors. However, you should check the surge protector’s manual to confirm this usage is allowed.
Professional grade or industrial surge protectors
In certain commercial or industrial settings, specially designed surge protectors are made to handle the demands of being plugged into another protector. These professional-grade models have higher joule ratings and maximum loads that allow daisy chaining if needed. Though it is still better to avoid chaining whenever possible.
Temporary, low-risk usage
Plugging one surge protector into another very briefly and infrequently to power a device or appliance may be low risk, though still not recommended. You should immediately unplug the setup afterwards. Do not leave two protectors plugged into each other unattended for long periods of time.
Tips for Safely Using Surge Protectors
Here are some tips for safely using surge protectors in your home or office:
- Always plug surge protectors directly into a wall outlet. Avoid extension cords and power strips without surge protection.
- Don’t overload the surge protector’s outlets. Check the maximum load rating and only plug in essential devices.
- Allow space around the protector for ventilation and cooling. Don’t cram them too close together.
- Use surge protectors with an adequate joule rating for the devices you are connecting.
- Periodically inspect your surge protectors for any signs of damage or malfunction.
- Don’t rely solely on surge protectors. Also utilize UPS battery backup systems for devices that need uninterrupted power.
- Unplug surge protectors when not in use to conserve energy. Many continue drawing a small amount of standby power when idle.
Conclusion
Plugging one surge protector into another surge protector is generally not recommended due to risks like overheating, fire hazards, reduced protection and bypassing of safety features. Exceptions can be made rarely and temporarily for low-risk situations or when using certain professional-grade surge protectors designed for daisy chaining. However, it is always best practice to plug surge protectors directly into wall outlets and avoid chaining them when possible. Safety comes first when using electrical devices.