FCV18-01
Single-Phase & DC Voltage Protection Relay with Direct Voltage Trip Settings
Simple, Direct Voltage Trip Settings — No Percentage Calculation Needed
The FCV18-01 is a voltage monitoring relay for single-phase AC and DC systems that features the simplest panel configuration in its class — just two touch buttons directly set the over-voltage trip voltage (U>) and the under-voltage trip voltage (U<) as actual voltage values. No Un selector, no percentage calculations, no complicated setup.
When the monitored voltage rises above U> or falls below U<, the relay trips (after the configured time delay Tt). This protects sensitive equipment in battery systems, solar installations, DC power supplies, and single-phase AC distribution — without requiring a technician to calculate percentage thresholds.
Quick Specifications
Why Choose the FCV18-01?
Simple, direct voltage trip settings — no percentage calculation, no voltage selector dial.
2-in-1 OV + UV Protection
Over-voltage and under-voltage monitoring in one compact relay — when voltage goes above U> or below U<, the relay trips.
Direct Voltage Trip Setting
No Un selector, no percentage calculations. Set U> and U< directly as voltage values — exactly the trip voltage you need.
16A SPDT Output Relay
High-capacity SPDT output handles direct motor and contactor switching. Mechanical life 10 million, electrical life 100,000 cycles.
Tool-Free Setup
Three front-panel touch button (U>, U<, Tt) — set the exact trip voltages you need with a screwdriver. No software or programming required.
AC & DC Universal Input
Dedicated AC models (A48/A220/A240) and DC models (D12/D48/D240) cover 9V to 270V AC/DC.
Protection Functions
Over-voltage and under-voltage monitoring with direct voltage trip settings.
The FCV18-01 monitors the system voltage continuously. The U> sets the over-voltage trip threshold as a direct voltage value — for example, setting U> to 250V means the relay will trip when the monitored voltage rises above 250V. The U< sets the under-voltage trip threshold directly — for example, setting U< to 190V means the relay trips when voltage falls below 190V.
There is no Un setting and no percentage setting — the trip voltages are set exactly as shown on the dials. When the monitored voltage exceeds U> or drops below U< and remains in that condition for the configured time delay Tt, the relay trips and opens the output contact.
1. Over-voltage Protection (U>)
When the monitored voltage rises above the U> trip voltage set directly on the dial and remains high for the configured time delay (Tt), the relay trips and opens the output contact. The U> setting is an absolute voltage value — no percentage calculation needed. For example, U> = 250V means trip when voltage exceeds 250V.
- Trip threshold: U> dial — set directly as a voltage value (e.g. 250V, 265V)
- Time delay: Tt setting (0.1s to 30s) must elapse before trip is confirmed
- Reset: Manual reset required even if voltage drops below the threshold
2. Under-voltage Protection (U<)
When the monitored voltage falls below the U< trip voltage set directly on the dial and remains low for the configured time delay (Tt), the relay trips. The U< setting is an absolute voltage value — for example, U< = 190V means trip when voltage drops below 190V. This protects battery systems, motors, and electronics from damage due to under-voltage.
- Trip threshold: U< dial — set directly as a voltage value (e.g. 190V, 207V)
- Application: Essential for battery backup systems, solar installations, and motor protection
- Reset: Manual reset required even if voltage drops below the threshold
Technical Specifications
Full electrical and mechanical specifications for the FCV18-01 series.
| Parameter | AC Models (A48 / A220 / A240) | DC Models (D12 / D48 / D240) |
|---|---|---|
| Voltage Type | Single-Phase AC | Single-Phase DC |
| Monitored Voltage Range | AC 20-80V (A48), AC 65-270V (A220/A240) | DC 9-18V (D12), DC 20-80V (D48), DC 65-270V (D240) |
| Over-voltage Setting (U>) | Direct voltage value (set on dial) | |
| Under-voltage Setting (U<) | Direct voltage value (set on dial) | |
| Time Delay (Tt) | 0.1s, 3s, 6s, 9s, 12s, 15s, 18s, 20s, 25s, 30s | |
| Measurement Accuracy | ΔV < ±1% | |
| Temperature Coefficient | 0.05%/°C at 20°C | |
| Output Contact | 1 × SPDT (NO+NC) | |
| Rated Current | 16A / 250V AC | |
| Mechanical Life | 1 × 10⁷ operations | |
| Electrical Life | 1 × 10⁵ operations | |
| Ambient Temperature | −20°C to +60°C | |
| Mounting | DIN Rail EN/IEC 60715 (35mm) | |
| Dimensions (H × W × D) | 90 × 18 × 64 mm | |
| Weight | 68g | |
| IP Rating | IP20 | |
| Standards | GB/T 14048.5, IEC 60947-5-1, EN 61812-1 | |
Other voltages available on request. Contact Fiicco for custom voltage configurations and OEM options.
Terminal Connections
SPDT relay output with screw-clamp terminals for fast, reliable wiring.
FCV18-01 Terminal Layout
- Always de-energize the panel before wiring
- Verify supply voltage matches the module rating (AC or DC model) before powering on
- Connect the positive and negative monitored voltage leads to the + and − terminals
- Terminal 11 = Common, 12 = NC, 14 = NO — wire your load to the appropriate contact
- Use correct wire gauge for 16A load current (min. 1.5mm²)
- Tighten terminal screws to 0.4 N·m torque specification
- Stripping length: 7mm (AWG13-20)
Front Panel & Settings
Three adjustment dials — no Un selector, no percentage calculation needed.
| Parameter | Description | Setting |
|---|---|---|
U> |
Over-voltage Trip Voltage — set directly as an absolute voltage value. When monitored voltage rises above this value, the relay trips. | Direct voltage value within model range (e.g. 250V, 265V) |
U< |
Under-voltage Trip Voltage — set directly as an absolute voltage value. When monitored voltage falls below this value, the relay trips. | Direct voltage value within model range (e.g. 190V, 207V) |
Tt |
Time Delay before trip — the delay period the relay waits before confirming a fault | 0.1s, 3s, 6s, 9s, 12s, 15s, 18s, 20s, 25s, 30s |
LED Indicator Panel
Power — Green LED
Lit = relay is powered on and system voltage is being monitored normally
R — Red LED
Lit = relay is in fault/trip state — output contact is open (tripped)
⚙ How to Set Parameters
- Set U>: Set the U> to the exact over-voltage trip voltage you need (e.g. 250V for a 230V system).
- Set U< : Set the U< to the exact under-voltage trip voltage you need (e.g. 190V for a 230V system).
- Set Tt: Choose the time delay (0.1s to 30s) to prevent nuisance tripping from brief voltage transients.
Key difference from typical voltage relays: There is no Un dial and no percentage calculation. The U> and U< dials set the exact trip voltage directly — no math required.
Models & Ordering
Choose the voltage range that matches your single-phase AC or DC system.
| Model Code | Voltage Type | Monitored Voltage Range | Manual |
|---|---|---|---|
| FCV18-01A48 | Single-Phase AC | AC 20V, 24V, 36V, 40V, 48V, 50V, 60V, 65V, 72V, 80V | PDF ↓ |
| FCV18-01A220 | Single-Phase AC | AC 65V, 110V, 120V, 127V, 130V, 150V, 190V, 200V, 208V, 220V | PDF ↓ |
| FCV18-01A240 | Single-Phase AC | AC 165V, 175V, 190V, 200V, 208V, 220V, 230V, 240V, 250V, 260V | PDF ↓ |
| FCV18-01D12 | Single-Phase DC | DC 9V, 10V, 12V, 13V, 14V, 15V, 16V, 17V, 18V | PDF ↓ |
| FCV18-01D48 | Single-Phase DC | DC 20V, 24V, 36V, 40V, 48V, 50V, 60V, 65V, 72V, 80V | PDF ↓ |
| FCV18-01D240 | Single-Phase DC | DC 65V, 110V, 120V, 127V, 130V, 150V, 190V, 200V, 208V, 220V | PDF ↓ |
FCV18 Family — Model Comparison
Compare the FCV18-01 and FCV18-02 models to find the right voltage protection relay for your application.
| Model | Over-voltage | Under-voltage | Trip Setting | Time Delay | Reset Mode | Phase Type | Ideal For |
|---|---|---|---|---|---|---|---|
| FCV18-01 | U> direct set | U< direct set | Direct voltage value | 0.1~30s | Manual Reset | Single-Phase AC & DC | Manual reset preferred — trip latch ensures fault is acknowledged before restart |
| FCV18-02 | U> direct set | U< direct set | Direct voltage value | 0.1~30s | Auto Reset | Single-Phase AC & DC | Automatic restart after voltage returns to normal — unattended systems |
Configuration Examples
Real-world setting examples — set U> and U< directly to the trip voltage you need.
FCV18-01A240 — 230V AC System
| U> (Over-voltage) | Set to 195V |
| U< (Under-voltage) | Set to 165V |
| Tt (Delay) | 0.1s |
FCV18-01A220 — 120V AC System
| U> (Over-voltage) | Set to 135V — trip above 135V |
| U< (Under-voltage) | Set to 100V — trip below 100V |
| Tt (Delay) | 0.1s |
FCV18-01D240 — 220V DC System
| U> (Over-voltage) | Set to 240V — trip above 240V |
| U< (Under-voltage) | Set to 200V — trip below 200V |
| Tt (Delay) | 0.1s |
See It In Action
Watch the FCV18-01 product overview and demonstration.
Typical Applications
The FCV18-01 protects single-phase AC and DC equipment across a wide range of industrial and commercial applications.
Battery Systems
Protect battery banks and charging circuits from over-charge and under-discharge voltage conditions.
Solar Installations
Monitor PV panel output and battery bank voltages in solar off-grid and hybrid systems.
DC Power Distribution
Protect DC distribution panels, PLC power rails, and telecom power supply systems.
Single-Phase Motors
Protect single-phase AC motors and pumps from voltage anomalies that cause overheating and failure.
Industrial Control
Protect PLC inputs, sensor power supplies, and industrial control circuits from voltage faults.
Ready to Order or Need More Details?
Download the full technical manual or contact the Fiicco team for pricing, samples, and OEM options.
Frequently Asked Questions
Common questions about the FCV18-01 single-phase and DC voltage protection relay
Most voltage relays require you to set a "rated voltage" (Un) and then calculate percentage thresholds (e.g. U> = Un + 10%). The FCV18-01 eliminates this complexity — the U> and U< dials set the exact trip voltage directly. If you need to trip at 250V, set U> to 250V. No Un selector, no math, no calculation errors.
The AC models (FCV18-01A48, A220, A240) are designed for alternating current single-phase systems and monitor AC voltage. The DC models (FCV18-01D12, D48, D240) are designed for direct current single-phase systems and monitor DC voltage. Both types provide the same over-voltage and under-voltage protection functions, but the input circuitry is tailored for AC or DC operation respectively.
Six voltage configurations are available: FCV18-01A48 (AC 20-80V), FCV18-01A220 (AC 65-270V), FCV18-01A240 (AC 165-260V), FCV18-01D12 (DC 9-18V), FCV18-01D48 (DC 20-80V), and FCV18-01D240 (DC 65-270V). Other voltages are available on request.
No. The FCV18-01 is designed for single-phase AC and DC systems only. For three-phase over-voltage, under-voltage, asymmetry, and phase sequence protection, consider the FCP18 series (FCP18-02, FCP18-03, FCP18-04, or FCP18-06) from Fiicco.
The time delay prevents nuisance tripping from brief voltage transients that naturally occur during motor starts, switching events, or load changes. Set Tt to a value that filters out normal transients while still protecting against genuine sustained fault conditions. The selectable delay steps are: 0.1s, 3s, 6s, 9s, 12s, 15s, 18s, 20s, 25s, and 30s.
The FCV18-01 has a single SPDT (single-pole double-throw) relay contact rated 16A/250V AC. Terminal 11 is the common, 12 is normally closed (NC), and 14 is normally open (NO). Wire your load between terminal 11 and terminal 14 for normally open operation — the circuit is energized when the relay trips.
Yes. Fiicco provides OEM services including custom branding (logo, model number, color), tailored specifications, and custom packaging for orders of 100+ units. Factory-direct pricing ensures competitive costs for OEM customers. Contact us at info@fiicco.com with your requirements and quantity for a tailored quotation.