Technical Documentation
DISOTIMER OBS-40AC AC Surge Protection Device Type 21.

Product Identity
Brand: SINOTIMER
Model: OBS-40
Type: AC surge protective device (SPD)
Configuration: 2 poles (L + N)
Protection class: Type 2 (T2)
Nominal AC voltage (Uc): 385 V AC
Nominal discharge current (In): 20 kA (8/20 µs)
Maximum discharge current (Imax): 40 kA (8/20 µs)
Protection level (Up): 1.8 kV
Compliance standards: IEC 61643-1, GB/T18802.1
Applications: Protection of single-phase AC electrical installations

General Description
The SINOTIMER OBS-40 AC protection device is designed for alternating current electrical installations, limiting transient overvoltages caused by indirect lightning strikes or network interruptions. The device protects connected equipment by diverting the surges to the grounding system. The OBS-40 model is designed for single-phase networks with L+N configuration, suitable for use in residential, commercial, or industrial electrical panels.

Visual Indicators and Operating Status
The device features a status indicator visible on the front of each unit. Green color indicates normal operation and active protection. Color change signals degradation of the internal component and the need to replace the unit. The indicator allows quick status confirmation without additional equipment.

Construction and Connection Positions
The protection device consists of two SPD units housed in a modular enclosure. The upper positions are clearly marked L (line) and N (neutral). The lower position is intended for grounding connection (PE). Connections are made via terminal screws, ensuring a safe and secure contact.

Protection Operation
The SINOTIMER OBS-40 Type 2 limits transient overvoltages on the AC network and reduces their level to a safe value for the protected equipment, with a protection level Up of 1.8 kV. It is designed to withstand repeated surge events within the specified nominal and maximum current limits.

Main Electrical Parameters
Maximum continuous AC voltage (Uc): 385 V AC
Nominal discharge current (In): 20 kA (8/20 µs)
Maximum discharge current (Imax): 40 kA (8/20 µs)
Protection level (Up): 1.8 kV
Test impulse type: 8/20 µs

Installation
Standard mounting on 35 mm DIN rail
Installation in single-phase AC panels
Direct and as short as possible connection to the grounding bar
Recommended installation as close as possible to the installation entry point or the protected equipment.

Usage Areas
Residential electrical panels
Commercial electrical panels
Protection of sensitive electronic equipment
Protection of single-phase AC circuits
Installations at risk of transient overvoltages

Important Notes
The device does not provide protection against overcurrents or short circuits and does not replace fuses or circuit breakers. Proper grounding connection is crucial for effective protection operation. If the visual indicator shows a fault, the unit must be replaced to maintain the protection level.