OVP

OVP

Over-Voltage Protector

Designed to address needs for an explosion-proof protection device,  the Over-Voltage Protector (OVP) line of products outperforms other protection products such as spark gap arresters and surge diverters. The OVP uses solid-state switching components to conduct at very low voltages, providing the most reliable over-voltage protection available to the industry. The OVP line of products is rated for AC fault current, as well as high values of lightning current, ensuring peak performance for the product’s long life.

The OVP was designed and has been tested to meet the requirements for Class I, Division 1 & 2, Group B, C, D classified locations in North America, and for Zone 1 requirements internationally. The model OVP is primarily used in Class I, Division 1 hazardous locations, requiring explosion-proof construction. For Division 2, Zone 2, or ordinary locations, see also the model OVP2.

Note: the OVP is not recommended where steady-state AC voltage exists between the connection points, typically induced AC voltage.

Features and Characteristics

  • UL, C-UL listed explosion-proof design: unique to the industry
  • IECEx certified for Zone 1 - UL
  • ATEX certified for Zone 1 - UL/DEMKO
  • The only fail-safe "arrester" on the market (i.e. fails shorted)
  • Solid-state design eliminates arcing
  • Conduction at much lower voltages than gapped arresters
  • Rated for AC fault current and lightning surge current
  • Suitable for submersed or above-ground locations
  • UL, C-UL listed explosion-proof design
  • Corrosion resistant nickel finish
  • EAC Certified Products Available - Learn More Here
    certifications
 
      
  • threshold voltage
  • -3/+1V (standard)
  • -2/+2V (standard)
  • up to -4/+4V (optional)
  • lightning surge current
  • 100kA crest (8 x 20 µs waveform)
  • environmental rating
  • NEMA 6P, IP68
  • hazardous (classified) areas
  • Class I, Divisions 1 & 2, Groups B, C, D, according to:
  • • NFPA 70 (US National Electric Code) sections 500-505
  • • UL 1203
  • • CSA C22.2 No.30-M1986 (R2012)
  • ATEX and IECEx for Zone 1 use for Gas Group IIB+H2 under protection method "d" according to: IEC60079-0:6th Edition; IEC60079-1:6th Edition; EN60079-0:2012; EN60079-1:2007
  • EAC: GOST R IEC 60079-1-2008, GOST R IEC 60079-0-2011
  • third-party listings and approvals
  • Underwriter's Laboratories (UL)
  • Underwriter's Laboratories - Canada (C-UL)
  • UL/DEMKO
  • NANIO-CCVE
See full Certifications/Listings for the OVP
AC Fault Current (amperes-rms) 50/60Hz
1 cycle 3 cycles 10 cycles 30 cycles
6,500 5,000 4,200 3,700
View Model Number Description Chart

The OVP has been tested by Nationally Recognized Testing Laboratories (NRTLs) for compliance to independent standards in its operation, ratings, and construction. This includes compliance to standards for:

SAFETY GROUNDING

UL (United States) and C-UL (Canada) listing for:

  • Providing an "effective ground-fault current path" as defined in NFPA 70 (US National Electrical Code - NEC), Article 250.2, and required in 250.4(A)(5)
  • Providing over-voltage protection in accordance with the applicable requirements of ANSI C62.11

BLOCKING CATHODIC PROTECTION CURRENT

  • Providing DC isolation of objectionable DC ground currents in grounding conductors as defined in NFPA 70, Article 250.6(E), and in CSA C22.1-12 Article 10-806

HAZARDOUS LOCATION USE

The OVP has been certified for use in Class I, Division 1 and 2, Groups B, C, D by UL and C-UL, according to:

    • NFPA 70 (U.S. National Electrical Code) sections 500-505
    • UL 1203
    • CSA C22.2 No.30-M1986 (R2012)

The OVP has been certified for Zone 2, Group II use by UL/DEMKO for meeting the ATEX Directive, according to EN 50021.

The OVP has been certified to the EAC requirements within TP TC 012/2011 for Zone Class 1 hazardous locations by NANIO-CCVE, according to:

  • GOST R IEC 60079-1-2008, GOST R IEC 60079-0-2011
OVP Model Numbers

Literature:
OVP - One Page Data Sheet
OVP - Technical Literature
OVP - Installation Instructions

Support Documents:
Certifications & Listings
Competitive Comparisons
OVP - Declaration of Conformity

Application Assistance:
Insulated Joint Protection
Decoupling Electric Equipment Grounding Systems
Airport Fueling Systems Isolation/Bonding

 

The OVP has been tested by various Nationally Recognized Testing Laboratories (NRTLs) for various aspects of its operation, ratings, and construction. These include:

SAFETY GROUNDING

UL (United States) and C-UL (Canada) listing for:

  • Providing an "effective ground-fault current path" as defined in 2002 NFPA 70 (US National Electrical Code - NEC), Article 250.2, and required in 250.4(A)(5)
  • Similarly, it meets the same per Canadian Standards Association CSA C22.2 No. 0.4-M1982 (reaffirmed 1999), using Canadian Electrical Code Part I, section 10-500, 10-806 as a guide.
  • Providing over-voltage protection in accordance with the applicable requirements of ANSI C62.11

Listing assures compliance to the above standards by DEI devices in providing electrical over-voltage protection and safety grounding.

BLOCKING CATHODIC PROTECTION CURRENT

  • Providing DC isolation of objectionable DC ground currents from cathodic protection systems as defined in NFPA 70, Article 250.6(E)

HAZARDOUS LOCATION USE

The OVP has been listed for use in Class I, Division 1 & 2, Groups B, C, D hazardous locations by UL and C-UL, according to:

  • U.S. National Electrical Code section 500-505
  • UL 1203: "Explosion-Proof and Dust-Ignition-Proof Electrical Equipment for Use in Hazardous (Classified) Locations"
  • CSA C22.2 No.30-M1986: "Explosion-Proof Enclosures for Use in Class I Hazardous Locations"

The OVP has also been tested by the Notified Body UL/Demko for conformity to ATEX directive 94/9/EC, according to the standard N50021:1999 "Electrical apparatus for potentially explosive atmospheres
- Type of protection 'n' and is certified for use in Zone 2.

See Declaration of Conformity to ATEX directive

Zinc Grounding

Comparison of Dairyland OVP to zinc grounding cells

Zinc Grounding Cells
These cells consist of two zinc rods, with insulation material to separate them, in a conductive backfill material, packaged in a bag. The insulation or separator leaves the zinc rods reasonably close together without touching. The backfill material, such as bentonite, promotes conduction and contact with the surrounding earth, as the package is buried near the points it is connected to. A wire lead attaches each rod to a point of interest, such as across an insulated flange, or between a pipeline and ground. The concept for protection is that the zinc rods will allow separation of the two structures, and minimize the DC cathodic protection current flow under normal conditions. Under over-voltage conditions, the small separation between the rods, and the conductive backfill will allow current to flow between them, draining the unwanted current.

There are several ways in which the zinc grounding cells will not perform very well for this application. First, the package must be buried. If the application is protection of insulated joints from over-voltage (lightning, for example), and the joint is above ground, the leads that connect to the joint will be at least several feet each. Under lightning surge conditions, this affords little or no over-voltage protection to the insulated joint, as leads have inductance, which lightning sees as a high impedance, and therefore creates a large voltage drop in the leads. Lightning protection for insulated joints is best done by locating a device directly across the joint, which cannot be done with zinc grounding cells, as compared to the Dairyland OVP.

Another electrical problem comes from AC power system fault current. Zinc grounding cells are generally not sized for handling any significant fault current.

Power laboratory testing to assure the performance of this product would be challenging, as this product is placed in service by burying in the earth, which would be difficult or impossible in a lab setting that could provide the needed values of lightning surge current or AC fault current. We have seen no test data for these products.

By separating the zinc rods in the package to achieve isolation, the question arises as to what voltage is allowed by the cell. Separation of two metallic surfaces by a medium (air, gases, solid insulation, semi-conductive backfill) has been common for over-voltage protection, but consistency of performance is an issue. Having the separation be consistent, producing a known, fixed clamping voltage is difficult if the product can vary in dimensions or construction. Consistency in over-voltage protection using a zinc grounding cell is in question, just as a spark gap arrester in air can vary during atmospheric changes due to moisture.

In addition, where the desire is to provide the lowest possible over-voltage on the structure during an event, a device should have a low impedance for conduction of current. This is not the case with a zinc grounding cell.

Dairyland OVP (Over-Voltage Protector):
As a comparison to the above description, consider the characteristics of the solid-state OVP. It is a blocking device in the normal mode. For all signals including DC (cathodic protection) current, it presents a very high impedance up to several volts, then appears as a short circuit for disturbances. When the event is over, the device automatically reverts to blocking DC current. There is no internal gap in the device, so over-voltage clamping occurs at a very low voltage - much lower than any other technology. Consistency in performance is assured through the use of tested power semiconductor components. The device has been designed so that it will even fail as a short circuit if exposed to currents beyond the rating, providing a fail-safe nature. The OVP has been tested in a power laboratory and is rated for lightning surge current and AC fault current.

OVP-3/1-3.7100
OVP-2/2-3.7-100
Quantity Weight Packaged Dimensions
1 7 8x8x3
2 13 9x9x12"
4 28 9x9x12"
8 56 20x12x10"

Note: For other OVP models or quantities, contact Dairyland for more information.