There are many electrical risks you have to protect against, one of the most concerning being voltage surges. These spikes in power can be extremely dangerous if you do not take the proper preventative steps. is devoted to providing companies the best in technology and putting safety first, which includes protecting against surges. They have a wide range of products, so it’s important you understand which are the best for you.
What is an Electrical Surge and Where Does it Come From?
Electrical surges are extremely brief spikes or disturbances up to tens of thousands of volts. These can damage or destroy your electronic equipment. Surges can come from external sources, such as lightning or utility grid switching.
However, most surges come from internal facility equipment:
- Inductive loads stopping and starting
- Lighting load panels turned on and off frequently
- HVAC systems
Why Do You Need Surge Protection?
is required in the 2017 National Electric Code (NEC), but there are many reasons why you would want it regardless. Surges can damage or destroy your property, result in downtime, and cause safety issues.
The cost of being unprotected is high, so it’s important to include power protection at the point of entry, as well as near your sensitive equipment.
How to Choose a Device
- Maximum Continuous Operating Voltage – Max RMS voltage that may be continuously applied to MOV
- Nominal Discharge Current – Stress test to measure durability of a product
- Voltage Protection Rating – Measurement of the limiting voltage (let-through or clamping voltage)
- Maximum Discharge Current of Surge Rating – Measurement of longevity (not an official UL measurement)
As mentioned, surges can come from internal or external sources, and it’s important that a system is protected where the power enters, as well as near the sensitive equipment. These different types of protection serve different purposes, and it’s important you put the correct type in the correct location.
The Institute of Electrical and Electronic Engineers (IEEE) have three location categories which correspond to the American National Standards Institute (ANSI) type designations.
- Type 1/Category C is designed to protect areas with a high risk of lighting strike, like incoming power supply panels, outside overhead lines, and service entrances.
- Type 2/Category B is designed to protect areas with a low risk of lightning strike, often downstream of Category C, such as feeders, short branch circuits, and indoor service panels.
- Type 3/Category A is designed to protect sensitive equipment such as outlets/receptacles or long branch circuits, and is always installed downstream of Category B.
Mersen SPD Products
These are board level components, such as Mersen’s TPMOV and VSP fuses, which include a disconnecting apparatus in the case of a surge event.
Thesecan be panel–mounted and wall–mounted for either the whole-facility or point-of-use equipment, and includes their STX and STZ series.
SPD DIN-Rail and SPD In-Line
These can be installed within industrial control cabinets, VFDs, disconnect switches or other power equipment for distribution, control and signaling.