Technical Article

Dairyland OVP Devices vs. Competing Technologies

Insulated joints are a crucial part of any operation where corrosion protection is needed, and they need a high level of current protection from lightning strikes and AC faults. If you have a larger application, you will have many joints that require over-voltage protection, both for your personnel and the joint itself. Spark gaps have often been used as lightning protection devices and do provide DC blocking. However, they fall short of an efficient, reliable, and safe solution when compared to more robust devices, due to their failure rate and replacement needs.

Enter the Dairyland Over-Voltage Protector. Our proven, solid-state design is the true solution for over-voltage concerns. Not only will you extend the life of your insulated joints by providing rugged, failsafe protection, you will be installing maintenance-free devices that have virtually unlimited lifespans. No need to schedule maintenance or budget for replacements; the OVP will still be there when you retire. Below, we outline several benefits Dairyland products can offer over gap arresters.

Device Operation

Spark gap arresters are made of two electrodes separated by a gap, usually filled with air. When the voltage between the electrodes exceeds the ability of the air gap to isolate, the current will arc over and flow through the device. They are made to respond to lightning, but usually require several hundreds or thousands of volts to arc. Spark gap devices cannot carry typical AC fault levels for any significant length of time and are not suitable for use with AC mitigation systems.

Dairyland’s Over-Voltage Protectors (OVP and OVP2) use high power solid-state electronic switching components to isolate DC current in cathodic protection systems from grounding paths. They also simultaneously provide a safe grounding path for AC fault and lightning events. Normally, the device remains open and isolates DC current to a specified threshold. During a lightning or AC fault event, the device closes and allows the high current to pass to ground. Once the over-voltage event has cleared, the device returns to normal DC isolation mode. This operation can be repeated virtually indefinitely. OVP devices are not recommended where steady-state AC exists between the connection points. For that specific application, we recommend a decoupler product like the SSD, PCR or PCRH, which are designed to mitigate induced AC.



Depending on your needs, Dairyland’s OVP or OVP2 will supply long-term protection of your equipment and personnel. If your application is in a Divison 1/Zone 1 hazardous location, choose OVP for its explosion-proof housing and rugged construction. If you are installing the unit in a Division 2/Zone 2 or non-hazardous location and just need an over-voltage protector for your insulated joints, but don’t have any AC mitigation needs, go with OVP2. Its solid-state components and fail-safe design will ensure a safe environment for your team members, efficient isolation and grounding for your equipment, and peace of mind for you.

Want To Dive Deeper?
Join One of Our Learning Events.

Our event schedule provides you the in-depth product and application training you need to correctly apply Dairyland products.

View Event Schedule