Product Overview
(1) Core positioning and applicable scenarios
Product Name: RCMA475LY AC/DC Sensitive Residual Current Monitor
Applicable systems: TN system, TT system (grounded power supply system)
Monitoring objects: alternating current (AC), direct current (DC), pulsating DC current
Typical applications: Scenarios with six pulse rectifiers or unidirectional rectification filtering loads, such as frequency converters, uninterruptible power supplies (UPS), battery chargers, construction site variable frequency drive equipment, etc
Core value: Identify continuous DC fault currents or residual currents greater than zero, and prevent electrical safety risks through warning and alarm mechanisms
(2) Compliance and Certification
Following standards: IEC/TR 60755 (Type B), EN 61543, EN 61000-6-4, IEC 60664-1 (Insulation Coordination), etc
Protection level: The shell material meets the UL94V-0 flame retardant standard
Core functions and operational features
(1) Monitoring and threshold setting
Specific parameter adjustability of functional items
Monitoring frequency range 0... 700Hz fixed
Alarm threshold (I Δ n1) 30... 500mA continuously adjustable
Warning threshold (I Δ n2) 50% I Δ n1 or 100% I Δ n1 DIP switch switching
Alarm response delay 0... 10s potentiometer adjustment (x1/x10 gear)
Warning response delayed by 0s or 1s DIP switch switching
(2) Key functions
Dual independent alarm relay: 2 conversion contacts, supporting NO (normally open)/NC (normally closed) operation mode switching (DIP switch setting), meeting different control circuit requirements.
Fault memory: The alarm status is automatically stored and needs to be manually cleared through the test/reset button for easy fault tracing.
Testing and Reset:
Built in: Combination button (short press<1s=reset, long press>2s=test).
External: Supports connecting external test/reset buttons (cable length is not explicitly limited and needs to be matched with the load).
Display function:
Power On LED: The device is constantly on during operation, but flashes when the measurement range exceeds the limit.
Alarm LED: It lights up when the alarm threshold is reached and flashes when the warning threshold is reached.
LED bar chart: displays the proportion of measured residual current to the set threshold at a scale of 0... 100%.

Detailed technical parameters
(1) Electrical parameters
Category specific specifications
Measurement current transformer built-in, inner diameter ø 18mm (PE conductor must not pass through)
Relative uncertainty of response value ≤ 25%
Lag characteristic ≤ 25% set response value (I Δ n)
Response time (at tv=0s) 1 times I Δ n1: ≤ 70ms; 5 times I Δ n1: ≤ 40ms
Relay parameter contact voltage: 150V AC/DC; Rated current: 5A (AC/DC); Connection capacity: 2A (AC 230V, cos φ=0.4); Breaking capacity: 0.2A (DC 220V, L/R=0.04s)
External measuring instrument interface current source output, 0... 400 µ A (corresponding to 0... 100% I Δ n), load ≤ 12.5k Ω
Supply voltage (by model) RCMA475LY: 230V AC/DC; RCMA475LY-13:90…132V AC/DC; RCMA475LY-21:9.6…84V AC/DC; RCMA475LY-23:77…286V AC/DC
Power consumption ≤ 3.5 VA
(2) Environmental and mechanical parameters
Category specific specifications
Working environment temperature -25...+70 ℃
Storage environment temperature -40...+75 ℃
Climate grade DIN IEC 60721-3-3 (3K5)
Impact resistance performance during operation: 15g/11ms (IEC 60068-2-27); During transportation: 40g/6ms (IEC 60068-2-29)
Vibration resistance performance during operation: 1g/10... 150Hz; During transportation: 2g/10... 150Hz (IEC 60068-2-6)
Installation method: Screw installation (hole diameter 4.3mm)
Shell weight ≤ 350g
The external dimensions refer to DIN 43871/IEC 60715 standard (specific dimensions: 99mm × 91mm × 45mm, subject to the actual product)
(3) Working characteristics of different current types
Current type Operating current range (relative to I Δ n) Remarks
AC current (50Hz) 0.5... 1 × I Δ n sine wave AC
Pulsating DC current (positive and negative half waves) 0.5... 1.4 × I Δ n with half wave rectified current
Phase controlled half wave current (delay angle 90 ° el/135 ° el) 0.5... 1.4 × I Δ n controllable rectifier load
Overlay 6mA smooth DC half wave current 0.5... 1.4 × I Δ n mixed DC+pulsating DC scene
Smooth DC current 0.5... 2 × I Δ n pure DC fault current
Model and ordering information
(1) Model differentiation and order number
Model, Supply Voltage, Applicable Scenarios, Order Number
RCMA475LY 230V AC/DC Industrial+Household B 9404 2002
RCMA475LY-13 90... 132V AC/DC Industrial B 9404 2004
RCMA475LY-21 9.6... 84V AC/DC Industrial B 9404 2014
RCMA475LY-23 77... 286V AC/DC Industrial B 9404 2015
Note: Other power supply voltage versions can be customized according to needs
(2) Recommended supporting components
Component Name Function Model Order Number
External measuring instrument 0... 100% residual current display (size 96 × 96mm) 9604-4241 B 986 807
Measurement converter input 0... 400 µ A, output 0... 10V/4... 20mA RK170 B 9804 1500
Installation and wiring points
The internal diameter of the built-in measuring current transformer is ø 18mm, and PE conductors are strictly prohibited from passing through the transformer to avoid measurement interference.
Email:wang@kongjiangauto.com