1. Introduction
This manual provides comprehensive instructions for the installation, operation, and maintenance of the Dwyer MCS-111050 Miniature Current Switch. The MCS-111050 is designed for monitoring current usage in various electrical applications, particularly within fuse boxes and small control panels. It features adjustable set points and LED indicators for operational status.
2. Safety Information
WARNING: Electrical shock hazard. Installation and servicing should only be performed by qualified personnel. Disconnect power before installation or maintenance to prevent injury or damage to equipment.
- Always follow local electrical codes and regulations.
- Ensure the power supply is disconnected before wiring or adjusting the device.
- Do not exceed the specified electrical ratings of the switch.
- Protect the device from moisture and extreme temperatures.
3. Product Overview
The Dwyer MCS-111050 is a miniature solid-core current switch designed for precise current monitoring. It is self-powered, requiring no external power supply for its operation. The device includes visual indicators (LEDs) for power and switch activation, along with a potentiometer for adjusting the current set point.
Figure 1: Dwyer MCS-111050 Miniature Current Switch. This image displays the compact black housing of the current switch, featuring a central through-hole for the monitored conductor. On the top surface, there are two LED indicators (red for 'ON' and green for 'High/Low' status) and a small adjustment potentiometer. A green screw terminal block is visible on the right side for output connections. The device also shows regulatory markings including CE and cULus LISTED.
Key Features:
- Current Sensing Range: 0.5 to 50 A continuous.
- Power Requirements: Self-powered, no external power needed.
- Temperature Limits: 32 to 122°F (0 to 50°C).
- Humidity Limits: 10 to 95% (non-condensing).
- Response Time: Less than 200 milliseconds.
- Enclosure Rating: UL 94V-0 flammability rated ABS, insulation class 600 V.
- Output Contact Type: Normally Open (NO).
- Switching Capacity (Max): 0.3A @ 130V AC/DC.
- Connection: Screw Terminals.
4. Setup and Installation
Before proceeding with installation, ensure all power to the circuit being monitored is disconnected.
4.1 Mounting
The MCS-111050 can be mounted using screws through the integrated mounting tabs. Choose a location that is free from excessive vibration, moisture, and extreme temperatures, and allows for easy access to wiring and adjustments.
4.2 Wiring Instructions
- Power Disconnection: Turn off all power to the circuit where the current switch will be installed. Verify with a voltage meter.
- Conductor Routing: Route the current-carrying conductor (the wire whose current you wish to monitor) through the sensing hole in the center of the MCS-111050 unit. For optimal sensitivity, ensure the conductor passes cleanly through the hole. Multiple passes (loops) through the hole can increase sensitivity for lower current applications, effectively multiplying the sensed current.
- Output Connection: Connect the control circuit wires to the screw terminals on the side of the current switch. The MCS-111050 provides a Normally Open (NO) contact. This means the contacts are open when the sensed current is below the set point and close when the current exceeds the set point. The maximum switching capacity is 0.3A at 130V AC/DC. If controlling a higher load, an intermediate relay or contactor must be used.
- Verify Connections: Double-check all wiring for secure connections and correct polarity.
4.3 Set Point Adjustment
The current set point is adjustable via a potentiometer located near the LED indicators. The sensing range is 0.5 to 50 A. Rotate the potentiometer using a small screwdriver:
- Counter-clockwise: Decreases the set point (activates at lower current).
- Clockwise: Increases the set point (activates at higher current).
The green LED indicates when the sensed current is above the set point and the switch is activated. The red LED indicates the presence of current in the monitored conductor.
5. Operating Instructions
Once installed and the set point is adjusted, the MCS-111050 operates automatically. When the current flowing through the sensing hole exceeds the set point, the internal switch contacts will close, activating the connected control circuit. When the current drops below the set point, the contacts will open.
LED Indicators:
- Red LED: Indicates the presence of current in the monitored conductor (power to the unit).
- Green LED: Illuminates when the sensed current exceeds the adjusted set point, indicating the switch is activated (contacts are closed).
6. Maintenance
The Dwyer MCS-111050 is designed for minimal maintenance. Periodic inspection is recommended to ensure optimal performance:
- Visual Inspection: Check for any signs of physical damage, discoloration, or loose connections.
- Connection Integrity: Ensure all screw terminals are tight and wires are securely connected.
- Environmental Conditions: Verify that the operating environment remains within the specified temperature and humidity limits.
- Functionality Check: Periodically test the switch operation by varying the load current to confirm it activates and deactivates at the desired set point.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Switch does not activate (Green LED off) |
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| Switch remains activated (Green LED on) |
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| Red LED is off |
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8. Specifications
| Model Number | MCS-111050 |
| Current Sensing Range | 0.5 to 50 A continuous |
| Power Requirements | None, self-powered |
| Temperature Limits | 32 to 122°F (0 to 50°C) |
| Humidity Limits | 10 to 95% (non-condensing) |
| Response Time | <200 ms |
| Enclosure Rating | UL 94V-0 flammability rated ABS, insulation class 600 V |
| Operating Voltage (Insulation Class) | 600 Volts |
| Contact Type | Normally Open (NO) |
| Switching Capacity (Max) | 0.3A @ 130V AC/DC |
| Connector Type | Screw Terminals |
| Manufacturer | Dwyer Instruments, Inc. |
9. Warranty
For detailed warranty information, please refer to the official Dwyer Instruments, Inc. website or contact their customer service. Warranty terms typically cover defects in materials and workmanship for a specified period from the date of purchase.
10. Technical Support
If you encounter any issues or have questions not covered in this manual, please contact Dwyer Instruments, Inc. technical support for assistance. Contact information can typically be found on the manufacturer's official website.
