ZA Series Radial Lead Varistors

Category: Electronics, Littelfuse Inc, Resistors

Description and Applications

The ZA Series comprises radial leaded varistors, also known as Metal Oxide Varistors (MOVs), that provide transient voltage surge suppression to safeguard low and medium-voltage circuits and systems. Typical utilization involves protecting components in motor control, telecom, automotive systems, solenoid, and power supply circuits, ensuring both component safety and data integrity. Varistors in this series are available in several sizes—5mm, 7mm, 10mm, 14mm, and 20mm—offering a broad voltage range capability from 5.5V to 615V, catering to diverse application requirements. Detailed specifications, including part numbers and brand information, are outlined in the device ratings and specifications table referenced within the datasheet.

Agency Approvals and Features

The ZA Varistor Series has received agency approvals, with relevant agency file numbers such as E135010 and E320116 for selected parts. The series emphasizes its environmental compliance by offering a lead-free and RoHS-compliant option.

Key Features:

This series provides a wide operating voltage range from 4V AC to 460V AC and from 5.5V DC to 615V DC.
Ambient temperature operation is maintained without derating up to 85°C.
Varistors come in five model sizes for flexible application needs.
The radial lead package suits both hard-wired or printed circuit board designs.
Options for packaging include tape and reel or bulk pack.
Several standard lead form options are available to accommodate different installation requirements.

Absolute Maximum Ratings

Absolute Maximum Ratings highlight the threshold that, if exceeded, may cause irreversible damage to the device. Ratings include a continuous steady-state applied voltage range of 4V to 460V AC, and 5.5V to 615V DC. The varistors can handle transient peak pulse currents ranging from 50A to 6500A with the corresponding single pulse energy range from 0.1J to 52J. They are designed to be used within an ambient temperature range of -55°C to +85°C and a storage temperature range from -55°C to +125°C. As for clamping voltage temperature coefficient, it’s specified at less than 0.01%/°C.

The encapsulation coating solution voltage capability is rated at 2500V, according to MIL STD-202, Method 301, indicating the varistor’s ability to withstand the specified DC voltage for one minute. Furthermore, the series boasts an insulation resistance of 1000 megaohms or more.

Users are cautioned that operation beyond the ‘Absolute Maximum Ratings’ can result in permanent damage to the varistor and is outside the recommended operating conditions.

For current specifications and more information, accessing the Littelfuse website and referring to the ZA series is advised. This information is based on the revision of the datasheet dated October 29, 2009. Changes in specifications are subject to occur without notice.