|
|
|
|
|
|
Inspection, Reconditioning and Testing of Low Voltage Surge Arresters
I. Introduction
The distribution class surge arrester is the most common type of protective device used on power systems today. Its application typically is limited to systems rated 34.5-kV and lower. The primary function of the distribution surge arrester is to protect the insulation of distribution class oil-filled transformers. Other typical applications include the protection of rotating machines and dry-type transformers. Most common in recent generations of arrestors is the MOV type or Metal Oxide Varistor type. Essentially, this device is installed just ahead of the load and it intercepts major voltage surges that might damage the transformer or motor.
The low voltage surge arrester is a sealed device. Reconditioning is limited to cleaning, refinishing metal surfaces as necessary, and testing. It is a relatively simple device but with major protective influence.
II. ComponentsBR>
Part and assemblies to be reconditioned under the proposed 1930 Low Voltage Surge Arresters standard include but are not limited to:
III. Testing and Inspection
The following test equipment is required to perform the testing requirements of this reconditioning standard:
1. Insulation Resistance Test Set (Megohmeter) 2500 Vdc minimum
Section II Recondition Evaluation-Inspection and Testing identifies each component and assembly part that must be inspected to determine the components viability and scope of reconditioning required to bring the component back to original operating condition. Results and notes from the pre-reconditioning inspection and test are recorded in the PEARL Reconditioning Evaluation and Test forms that accompany each low voltage surge arresters standard.
IV. Reconditioning
Assembly of the reconditioned components and subassemblies is followed by final inspection and testing. As with all testing, inspection, and reconditioning operations, final inspection and test results are recorded onto the Evaluation and Test forms included with the standard. If a PEARL certified technician follows the reconditioning standard, the low voltage surge arresters assembly is eligible for a Blue PEARL Reconditioned Quality Seal.
Links to the full proposed standard for low voltage surge arresters:
Home || About PEARL || Contact Us || Membership Information || Members || News || Safety News Newsletters || Photo Galleries || Videos || Electrical Standards || Links Members Only Intranet || Members Only Forum |