Electrical Fire Current-Limiting Protector
Microsecond current limiting: protection time <150μs, with overvoltage, undervoltage, overload, earth leakage and overtemperature protection in 20A and 40A ratings.
Overview
Key Features
Microsecond current limiting
Current-limiting protection time <150μs, cutting fault current quickly.
Multiple electrical protections
Overvoltage, undervoltage, overload, earth leakage and overtemperature monitored together.
Adjustable leakage monitoring
Earth leakage protection continuously adjustable from 30~1000mA.
Alarm mode selection
Four alarm modes, including alarm only or alarm plus trip.
RS485 communication
Operating status and alarms uploaded to the monitoring system.
DIN rail mounting
Standard 35mm DIN rail, installed inside the enclosure.
Technical Data
| Rated operating voltage | 220V±10% 50Hz |
| Rated current | 20A (5~20 adjustable) / 40A (10~40 adjustable) |
| Current-limiting protection time | <150μs |
| Overload protection | Above rated current and below short-circuit current |
| Undervoltage protection | 150~200V adjustable (factory 160V) |
| Overvoltage protection | 235~276V adjustable (factory 275V) |
| Earth leakage protection | 30~1000mA adjustable (factory 500mA) |
| Overtemperature protection | 40~120℃ adjustable (factory 80℃) |
| Display | LCD plus LED indicators |
| Alarm | Sound and light alarm, four modes selectable |
| Communication | RS485, baud rate up to 115200 |
| Mounting | Standard 35mm DIN rail |
Models & Selection
| Parameter | YSF-11120-R (XL-F20A) | YSF-11140-R (XL-F40A) |
|---|---|---|
| Rated operating voltage | 220V±10% 50Hz | 220V±10% 50Hz |
| Rated current | 20A (5~20 adjustable) | 40A (10~40 adjustable) |
| Current-limiting protection time | <150μs | <150μs |
| Earth leakage protection | 30~1000mA adjustable (factory 500mA) | 30~1000mA adjustable (factory 500mA) |
| Overtemperature protection | 40~120℃ adjustable (factory 80℃) | 40~120℃ adjustable (factory 80℃) |
Model naming rule：YSF-11120-R（XL-F20A） YSF-11140-R（XL-F40A）
Installation
FAQ
How do I choose between the 20A and 40A versions?
Select by the design current of the final circuit: the 20A version is adjustable from 5~20A and the 40A version from 10~40A. Model YSF-11120-R is the 20A unit and YSF-11140-R the 40A unit.
How fast is the current-limiting protection?
The current-limiting protection time is <150μs, so the fault current is cut in the early stage of its rise. The 20A and 40A versions share the same protection time.
Which other parameters are monitored?
Overvoltage 235~276V, undervoltage 150~200V, earth leakage 30~1000mA and overtemperature 40~120℃ are monitored, and all four thresholds are adjustable. Factory settings are 275V, 160V, 500mA and 80℃.
How are alarms and communication handled?
The front panel provides an LCD with LED indicators and a sound and light alarm, with four alarm modes to choose from. RS485 uploads operating status and alarm information to the monitoring system.
What certification applies and how is pricing provided?
Certification is held through a CE / CMA / CNAS accredited laboratory. Price and lead time are quoted per rating; Request a quote with the model code and the 20A or 40A rating required.