Mini-Current-Switch

Supported Applications

The ACI Miniature Fixed Current Switch series (MCS and MSCS) provides fixed trip point monitoring for the 'Go/No Go' status of equipment powered by AC current. These switches are designed to monitor motors, pumps, compressors, and similar machinery on the line side of power. The series supports local alarms, process control applications, and logging equipment run time.

Available in solid-core (A/MCS) and split-core (A/MSCS) configurations, the split-core version is suitable for retrofit installations where disconnecting wires is not feasible. Power is induced directly from the monitored conductor; therefore, these switches are intended for use with insulated conductors only.

Operating Conditions & Performance

The series monitors AC current within a range of 0 to 150A and supports maximum AC voltages up to 600 VAC. The operating frequency range is specified as 50/60 Hz, with an isolation voltage rating of 2200 VAC.

Performance parameters vary by core style:

• A/MCS (Solid-Core): Response time < 50 mS typical; Trip point at 0.20A or less.
• A/MSCS (Split-Core): Response time < 40 mS typical; Trip point at 0.55A or less.

The switches operate within an ambient temperature range of -22 to 140°F (-30 to 60°C) and a humidity range of 0 to 95%, non-condensing. Recommended storage conditions are 41 to 95°F (5 to 35°C) at 40 to 85% RH, non-condensing.

Configuration Options

The series offers two primary configurations distinguished by core style and trip point sensitivity. Both models feature a Normally-Open 'N/O' contact type with a status contact rating of 0.5A Continuous @ 36 VAC/VDC.

• Core Styles: Solid-core (A/MCS) for new installations; Split-core (A/MSCS) for retrofit applications without wire disconnection.
• Aperture Size: 0.53" (13.46 mm).
• Housing Material: PC/ABS (Polycarbonate/ABS Blend), UL94-V0 flammability rating.
• Electrical Connections: 2 Position Screw Terminal Block, not polarity sensitive. Supports wire sizes of 16 to 22 AWG (1.31 mm² to 0.33 mm²) copper wires only with a terminal block torque rating of 4.43 to 5.31 in-lbs. (0.5 to 0.6 Nm).
• Approvals: UL/CUL US Listed (UL 916) Energy Management Equipment (File # E334792), CE, RoHS2, WEEE.

The switches are rated for indoor use with a pollution degree of 2. Installation requires maintaining a minimum mounting distance of 1" (2.6 cm) between the current switch and other magnetic devices such as relays, contactors, or transformers to prevent interference.

Key Product Differences

The A/MCS model is a solid-core unit with dimensions of 2.510" x 0.940" x 2.000" (63.82 mm x 23.94 mm x 50.80 mm) and weighs 0.15 lbs (0.068 kg). It features a trip point of 0.20A or less.

The A/MSCS model is a split-core unit with dimensions of 2.650" x 0.940" x 2.380" (67.19 mm x 23.94 mm x 60.49 mm) and weighs 0.20 lbs (0.091 kg). It features a trip point of 0.55A or less.

Both models share identical contact resistance specifications: < 0.5 Ohms when tripped and greater than 1 Meg ohm when open. Neither model is intended for life/safety applications, hazardous locations, or classified environments. Maximum wire length should not exceed 98.4 Feet (30 meters) to meet CE requirements.