Sinetamer LA-ST240 Parallel 277V – 380V Transient Voltage Surge Supressor

The SineTamer© LA series of units blends outstanding high-energy “impulse” suppression with unsurpassed “ring-wave” transient protection. This durable device is intended for general purpose and sensitive/critical load applications. The LA-ST240 is typically installed at service entrances up to 2400 amps, distribution and sub-distribution panels. Compact size and non-metallic enclosure design also allow it to be installed directly inside electrical panels and individual equipment disconnects. The internal installation provides the absolute shortest possible lead length and optimum performance. The LA-ST240 is extremely effective in limiting internally generated transients and is an absolute must on panels feeding office locations and/or microprocessor based equipment. This economical device has features that are not available in devices costing many times its price. Its compact size makes installation a breeze. Maintenance Free operation and 20 Year Unlimited Free Replacement Warranty provide peace of mind. Standard unit is Type 2 10kA UL Nominal Discharge Current; Optional Type 220kA IN is available.


  • Application


    Designed for use at ANSI/IEEE Categories C, B and A with susceptibility up to medium exposure levels. Designed to protect sensitive/critical loads fed from distribution panels, branch panels and/or individual equipment panels.

Technical Specification

Parallel connected, transient voltage surge suppressor device utilizing both high-energy
handling and sine-wave tracking circuitry for virtual elimination of impulse and ring wave
type transients
High strength ABS Plastic, Nema 4 and IP66 rated
1” conduit fitting (internally threaded) and external mounting feet.
Connection Method
#10 stranded wire.
Circuit Design...
(10 modes for 3 phase wye units*) and utilizing our encapsulated design to provide
improved durability.
...Circuit Design
All suppression circuits are encapsulated in our exclusive compound to assure long component life and complete protection from the environment and/or vibration.
Protection Modes
Dedicated protection components and circuitry for each mode. Discrete L-N, L-L (Normal Mode), and Discrete L-G, N-G (Common Mode). 10 modes / 3 phase wye system.
Input Power Frequency
50- 60Hz
EMI/RFI Noise Attenuation
40dB Max. from 1kHz to 10MHz (normal and common mode)
LA-STB = Type 2 20kA IN Type 1 available – contact factory for proper model number.
Circuit Diagnostics
Super Bright LED, 1 per phase, normally on. Dry relay contacts for remote monitoring.
Circuit Interrupt
External and internal (see installation instructions for details).
Line level and component level thermal cutouts (see installation sheet for full details)