ZIP Intermediate Class Polymer Arresters

Features:

The type "ZIP" intermediate class arresters offer the benefits of polymer housings for system voltages up to 161kV. The arresters are approxiately 1/5 the weight of the porcelain equivalent. Handling and installation become much easier tasks. Also, the risk of damage to the housing is reduced compared to
porcelain.

Design:

The design consists of a number of metal oxide valve elements contained within a fiberglass winding and then inserted into the polymer housing. ZIP arresters are shippped as single units for all ratings. There is no need to combine sections, even for the 144kV duty cycle rating. The metal oxide valve elements combine excellent protective characteristics with steady state performance to
maximize protection over many years of service.

Performance:

ZIP: 3 through 144kV duty cycle rating, 2.55kV through 115kV MCOV for 2.4 through 161kV system line-line voltage.
The arrester designs are tested in accordance with the latest industry standards for metal oxide arresters. The "ZIP" arresters consistently withstand the following minumum design tests.
High Current-Short 1. Duration: 100kA crest

1. Transmission Line Discharge: Exceeds ANSI/IEEE and IEC class 2 standard requirements
2. Nominal discharge 3. current per IEC: 10kA
3. Minumum energy Capability: 5.0kJ/kV MCOV
4. Fault Withstand Capability: 50kA rms sym
5. Working cantilever strength: 5000 in. -lbs.
6. REA listed

Fault Current Withstand:

The severity of a failure depends on the duration and magnitude of the available fault current conducting through the arrester at the time of the failure. This type of arrester, with its polymer housing, eliminates the potential danger of porcelain fragmentation. The design uses a fiberglass epoxy wrap to relieve the pressure that is present during a failure.

Reliability:

Each completed "ZIP" arrester unit must pass the following electrical tests: reference voltage, power loss, total leakage current and RIV. These tests are in addition to the 100% production testing performed on the metal oxide valve elements. Each arrester is also subjected to a helium mass spectrometer leak test to insure the integrity of the sealing system.

Three Phase Installation Layout:

The holes for mounting are .56 inches (14.2 mm) for 1/2" bolts. Mounting bolts and washers are not furnished with the arrester.

Nameplates:

In addition to the information that is included on the tripod base, a namelate is attached to the casting to provide all of the required arrester details. The catalog
number, the rated voltage, the maximum continuous operating voltage, and the pressure relief current rating are shown. The serial number includes information about the time of manufacture.