✨ New Arrivals Just Dropped!Explore
Projoy Firefighter Safety Switch 10 Pole 5 Strings with MC4 20A per String
The Projoy PEFS-EL Firefighter Safety Switch — 10-Pole, 5-String, 20A provides simultaneous string-level rapid shutdown for up to five PV strings from a single compact unit, suited to residential and small C&I systems in the 3–8 kWp range. Mounted close to the array, it disconnects the up-to-1500V DC hazard between the panels and the inverter. Triggered by AC grid loss (≥5 seconds), internal temp sensor (≥70°C) or manual emergency stop. Auto-resets when AC power is restored. All DC inputs pre-wired with MC4 connectors. Rated 1500V DC, 20A per string. IP65, UL 94 V-0, EN 60947-1&3. Controlled via AC circuit — no Wi-Fi, no RF, no networking required.
10-pole
5 Strings
20A
Per String
1500V
Max DC
IP65
Rated
Auto
Reset
EN 60947
Certified
⚠ Qualified Installer Required: PV system components must be installed by a suitably qualified and competent person in accordance with BS 7671, IEC 60364-7-712 and MCS installation standards.
Key Features
5-String Coverage — One Device for Mid-Size Arrays
At 10 poles across 5 strings, this single unit replaces five separate string isolators. Suitable for 3–8 kWp arrays where multiple strings feed a multi-MPPT inverter. All five strings are controlled by a single AC supply connection — the control wiring is no more complex than the 2-string variant.
5 strings3–8 kWpSingle AC connection
Three Independent Shutdown Triggers — Any One Alone Is Sufficient
The PEFS-EL responds to three separate events, each capable of triggering automatic shutdown independently: (1) AC grid loss for more than 5 seconds — matches international firefighter procedure of cutting AC supply first before tackling the fire; (2) Internal enclosure temperature reaching 70°C — detected by a built-in sensor that monitors the enclosure interior in real time, triggering shutdown before the enclosure becomes a fire hazard itself; (3) Manual emergency stop button on the enclosure face for immediate on-site override.
AC loss ≥5s70°C temp sensorManual stop button
Automatic Reset — Resumes Generation After Routine Grid Outages
Unlike a one-shot fuse, the PEFS-EL resets automatically when AC power is restored after any automatic shutdown. For routine grid outages, ISP maintenance, load shedding or momentary supply interruptions, the system will re-close and resume generation without any manual intervention. Manual reset is only required after activation of the emergency stop button.
Auto-reset on AC restoreNo manual reset for grid outagesMinimises lost generation
Motor-Driven Energy-Storage Spring — 5ms Arc-Quench
Each pole is opened by a motor-driven energy-storage spring mechanism that releases on trigger, driving the contacts apart in under 5 milliseconds. DC arcs have no zero-crossing point and sustain indefinitely if contacts separate slowly — the 5ms response is specifically designed to stretch and quench the DC arc before it can cause contact damage, tracking or fire. Self-cleaning contacts reduce resistance build-up over the device lifetime.
5ms trip responseEnergy-storage springDC arc-quench mechanismSelf-cleaning contacts
MC4 Connectors — Direct Plug-In to Panel String Cables
DC string inputs are pre-wired with MC4 connectors — the universal standard connector used on virtually all solar panels. No stripping, crimping or ferrule insertion required on the DC side. The AC control cable enters via a standard IP65 cable gland.
MC4 pre-wiredNo DC termination workAC gland entry
IP65 Polycarbonate Enclosure — V-0 Flame Retardant
The enclosure is IP65-rated polycarbonate — fully dustproof and protected against water jets from any direction. The body material carries a UL 94 V-0 flame-retardant rating, meaning it will not propagate flame even if exposed to a direct ignition source. Suitable for rooftop, loft or external wall mounting.
IP65UL 94 V-0 flame retardantOutdoor-rated
AC-Circuit Controlled — No Wi-Fi, No RF, No Pairing Required
The PEFS-EL is controlled entirely by the existing AC supply circuit. When AC is present, the switch is closed. When AC drops for 5 seconds, the switch opens. No wireless communication module, no pairing sequence, no signal cable to run from the roof. The control logic is deterministic and immune to network failure — critical for a life-safety device.
AC-circuit logicNo Wi-Fi / RFDeterministic failsafeNo configuration
Technical Specifications
| PEFS-EL — 10-Pole 5-String 20A | |
| Number of Poles | 10 (2 per string, 5 strings) |
| Number of Strings | 5 |
| Rated Current per String | 20A |
| Max Loop Voltage (DC) | 1500V DC |
| String Voltage Range | 300–1500V DC |
| AC Control Voltage | 100–270V AC |
| AC Nominal Voltage | 230V AC |
| Feedback (FB) Contact | Not included — see FB variant |
| DC Connector Type | MC4 (pre-wired) |
| Triggers and Behaviour | |
| Auto Shutdown: AC Loss | Opens after AC loss ≥5 seconds |
| Auto Shutdown: Temperature | Opens when internal temp ≥70°C |
| Manual Shutdown | Emergency stop button on enclosure |
| Auto Reset | Yes — auto-closes when AC power restored |
| Switching Speed | <5ms (energy-storage spring mechanism) |
| Physical and Environmental | |
| Protection Rating | IP65 |
| Flame Retardant Rating | UL 94 V-0 (enclosure body) |
| Operating Temperature | −20°C to +50°C |
| Auto-Trip Temperature | +70°C (internal enclosure) |
| Storage Temperature | −40°C to +85°C |
| Protection Class | Class II |
| Standards and Certifications | |
| Test Standard | EN 60947-1 & 3 |
| Certifications | CE, ISO 9001, ISO 14001 |
| DC Switch Standard | IEC 60947-3 (ed.3.2):2015, UL508i, GB14048.3 |
| Utilisation Category | DC-PV0 / DC-PV1 |
| Mechanical Life | |
| Operations (total) | 10,000 |
| Operations under load (PV1) | >1,500 |
| Manufacturer | |
| Manufacturer | Projoy Electric Co., Ltd. |
Frequently Asked Questions
Related Products
Projoy Battery Isolator with Enclosure (PEBS-L)
DC MCB for battery-inverter circuits
Projoy DC Surge Protector (PESP)
SPD for DC PV string protection
$159.19
Original: $454.84
-65%Projoy Firefighter Safety Switch 10 Pole 5 Strings with MC4 20A per String—
$454.84
$159.19More Images
Projoy Firefighter Safety Switch 10 Pole 5 Strings with MC4 20A per String
The Projoy PEFS-EL Firefighter Safety Switch — 10-Pole, 5-String, 20A provides simultaneous string-level rapid shutdown for up to five PV strings from a single compact unit, suited to residential and small C&I systems in the 3–8 kWp range. Mounted close to the array, it disconnects the up-to-1500V DC hazard between the panels and the inverter. Triggered by AC grid loss (≥5 seconds), internal temp sensor (≥70°C) or manual emergency stop. Auto-resets when AC power is restored. All DC inputs pre-wired with MC4 connectors. Rated 1500V DC, 20A per string. IP65, UL 94 V-0, EN 60947-1&3. Controlled via AC circuit — no Wi-Fi, no RF, no networking required.
10-pole
5 Strings
20A
Per String
1500V
Max DC
IP65
Rated
Auto
Reset
EN 60947
Certified
⚠ Qualified Installer Required: PV system components must be installed by a suitably qualified and competent person in accordance with BS 7671, IEC 60364-7-712 and MCS installation standards.
Key Features
5-String Coverage — One Device for Mid-Size Arrays
At 10 poles across 5 strings, this single unit replaces five separate string isolators. Suitable for 3–8 kWp arrays where multiple strings feed a multi-MPPT inverter. All five strings are controlled by a single AC supply connection — the control wiring is no more complex than the 2-string variant.
5 strings3–8 kWpSingle AC connection
Three Independent Shutdown Triggers — Any One Alone Is Sufficient
The PEFS-EL responds to three separate events, each capable of triggering automatic shutdown independently: (1) AC grid loss for more than 5 seconds — matches international firefighter procedure of cutting AC supply first before tackling the fire; (2) Internal enclosure temperature reaching 70°C — detected by a built-in sensor that monitors the enclosure interior in real time, triggering shutdown before the enclosure becomes a fire hazard itself; (3) Manual emergency stop button on the enclosure face for immediate on-site override.
AC loss ≥5s70°C temp sensorManual stop button
Automatic Reset — Resumes Generation After Routine Grid Outages
Unlike a one-shot fuse, the PEFS-EL resets automatically when AC power is restored after any automatic shutdown. For routine grid outages, ISP maintenance, load shedding or momentary supply interruptions, the system will re-close and resume generation without any manual intervention. Manual reset is only required after activation of the emergency stop button.
Auto-reset on AC restoreNo manual reset for grid outagesMinimises lost generation
Motor-Driven Energy-Storage Spring — 5ms Arc-Quench
Each pole is opened by a motor-driven energy-storage spring mechanism that releases on trigger, driving the contacts apart in under 5 milliseconds. DC arcs have no zero-crossing point and sustain indefinitely if contacts separate slowly — the 5ms response is specifically designed to stretch and quench the DC arc before it can cause contact damage, tracking or fire. Self-cleaning contacts reduce resistance build-up over the device lifetime.
5ms trip responseEnergy-storage springDC arc-quench mechanismSelf-cleaning contacts
MC4 Connectors — Direct Plug-In to Panel String Cables
DC string inputs are pre-wired with MC4 connectors — the universal standard connector used on virtually all solar panels. No stripping, crimping or ferrule insertion required on the DC side. The AC control cable enters via a standard IP65 cable gland.
MC4 pre-wiredNo DC termination workAC gland entry
IP65 Polycarbonate Enclosure — V-0 Flame Retardant
The enclosure is IP65-rated polycarbonate — fully dustproof and protected against water jets from any direction. The body material carries a UL 94 V-0 flame-retardant rating, meaning it will not propagate flame even if exposed to a direct ignition source. Suitable for rooftop, loft or external wall mounting.
IP65UL 94 V-0 flame retardantOutdoor-rated
AC-Circuit Controlled — No Wi-Fi, No RF, No Pairing Required
The PEFS-EL is controlled entirely by the existing AC supply circuit. When AC is present, the switch is closed. When AC drops for 5 seconds, the switch opens. No wireless communication module, no pairing sequence, no signal cable to run from the roof. The control logic is deterministic and immune to network failure — critical for a life-safety device.
AC-circuit logicNo Wi-Fi / RFDeterministic failsafeNo configuration
Technical Specifications
| PEFS-EL — 10-Pole 5-String 20A | |
| Number of Poles | 10 (2 per string, 5 strings) |
| Number of Strings | 5 |
| Rated Current per String | 20A |
| Max Loop Voltage (DC) | 1500V DC |
| String Voltage Range | 300–1500V DC |
| AC Control Voltage | 100–270V AC |
| AC Nominal Voltage | 230V AC |
| Feedback (FB) Contact | Not included — see FB variant |
| DC Connector Type | MC4 (pre-wired) |
| Triggers and Behaviour | |
| Auto Shutdown: AC Loss | Opens after AC loss ≥5 seconds |
| Auto Shutdown: Temperature | Opens when internal temp ≥70°C |
| Manual Shutdown | Emergency stop button on enclosure |
| Auto Reset | Yes — auto-closes when AC power restored |
| Switching Speed | <5ms (energy-storage spring mechanism) |
| Physical and Environmental | |
| Protection Rating | IP65 |
| Flame Retardant Rating | UL 94 V-0 (enclosure body) |
| Operating Temperature | −20°C to +50°C |
| Auto-Trip Temperature | +70°C (internal enclosure) |
| Storage Temperature | −40°C to +85°C |
| Protection Class | Class II |
| Standards and Certifications | |
| Test Standard | EN 60947-1 & 3 |
| Certifications | CE, ISO 9001, ISO 14001 |
| DC Switch Standard | IEC 60947-3 (ed.3.2):2015, UL508i, GB14048.3 |
| Utilisation Category | DC-PV0 / DC-PV1 |
| Mechanical Life | |
| Operations (total) | 10,000 |
| Operations under load (PV1) | >1,500 |
| Manufacturer | |
| Manufacturer | Projoy Electric Co., Ltd. |
Frequently Asked Questions
Related Products
Projoy Battery Isolator with Enclosure (PEBS-L)
DC MCB for battery-inverter circuits
Projoy DC Surge Protector (PESP)
SPD for DC PV string protection
Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
The Projoy PEFS-EL Firefighter Safety Switch — 10-Pole, 5-String, 20A provides simultaneous string-level rapid shutdown for up to five PV strings from a single compact unit, suited to residential and small C&I systems in the 3–8 kWp range. Mounted close to the array, it disconnects the up-to-1500V DC hazard between the panels and the inverter. Triggered by AC grid loss (≥5 seconds), internal temp sensor (≥70°C) or manual emergency stop. Auto-resets when AC power is restored. All DC inputs pre-wired with MC4 connectors. Rated 1500V DC, 20A per string. IP65, UL 94 V-0, EN 60947-1&3. Controlled via AC circuit — no Wi-Fi, no RF, no networking required.
10-pole
5 Strings
20A
Per String
1500V
Max DC
IP65
Rated
Auto
Reset
EN 60947
Certified
⚠ Qualified Installer Required: PV system components must be installed by a suitably qualified and competent person in accordance with BS 7671, IEC 60364-7-712 and MCS installation standards.
Key Features
5-String Coverage — One Device for Mid-Size Arrays
At 10 poles across 5 strings, this single unit replaces five separate string isolators. Suitable for 3–8 kWp arrays where multiple strings feed a multi-MPPT inverter. All five strings are controlled by a single AC supply connection — the control wiring is no more complex than the 2-string variant.
5 strings3–8 kWpSingle AC connection
Three Independent Shutdown Triggers — Any One Alone Is Sufficient
The PEFS-EL responds to three separate events, each capable of triggering automatic shutdown independently: (1) AC grid loss for more than 5 seconds — matches international firefighter procedure of cutting AC supply first before tackling the fire; (2) Internal enclosure temperature reaching 70°C — detected by a built-in sensor that monitors the enclosure interior in real time, triggering shutdown before the enclosure becomes a fire hazard itself; (3) Manual emergency stop button on the enclosure face for immediate on-site override.
AC loss ≥5s70°C temp sensorManual stop button
Automatic Reset — Resumes Generation After Routine Grid Outages
Unlike a one-shot fuse, the PEFS-EL resets automatically when AC power is restored after any automatic shutdown. For routine grid outages, ISP maintenance, load shedding or momentary supply interruptions, the system will re-close and resume generation without any manual intervention. Manual reset is only required after activation of the emergency stop button.
Auto-reset on AC restoreNo manual reset for grid outagesMinimises lost generation
Motor-Driven Energy-Storage Spring — 5ms Arc-Quench
Each pole is opened by a motor-driven energy-storage spring mechanism that releases on trigger, driving the contacts apart in under 5 milliseconds. DC arcs have no zero-crossing point and sustain indefinitely if contacts separate slowly — the 5ms response is specifically designed to stretch and quench the DC arc before it can cause contact damage, tracking or fire. Self-cleaning contacts reduce resistance build-up over the device lifetime.
5ms trip responseEnergy-storage springDC arc-quench mechanismSelf-cleaning contacts
MC4 Connectors — Direct Plug-In to Panel String Cables
DC string inputs are pre-wired with MC4 connectors — the universal standard connector used on virtually all solar panels. No stripping, crimping or ferrule insertion required on the DC side. The AC control cable enters via a standard IP65 cable gland.
MC4 pre-wiredNo DC termination workAC gland entry
IP65 Polycarbonate Enclosure — V-0 Flame Retardant
The enclosure is IP65-rated polycarbonate — fully dustproof and protected against water jets from any direction. The body material carries a UL 94 V-0 flame-retardant rating, meaning it will not propagate flame even if exposed to a direct ignition source. Suitable for rooftop, loft or external wall mounting.
IP65UL 94 V-0 flame retardantOutdoor-rated
AC-Circuit Controlled — No Wi-Fi, No RF, No Pairing Required
The PEFS-EL is controlled entirely by the existing AC supply circuit. When AC is present, the switch is closed. When AC drops for 5 seconds, the switch opens. No wireless communication module, no pairing sequence, no signal cable to run from the roof. The control logic is deterministic and immune to network failure — critical for a life-safety device.
AC-circuit logicNo Wi-Fi / RFDeterministic failsafeNo configuration
Technical Specifications
| PEFS-EL — 10-Pole 5-String 20A | |
| Number of Poles | 10 (2 per string, 5 strings) |
| Number of Strings | 5 |
| Rated Current per String | 20A |
| Max Loop Voltage (DC) | 1500V DC |
| String Voltage Range | 300–1500V DC |
| AC Control Voltage | 100–270V AC |
| AC Nominal Voltage | 230V AC |
| Feedback (FB) Contact | Not included — see FB variant |
| DC Connector Type | MC4 (pre-wired) |
| Triggers and Behaviour | |
| Auto Shutdown: AC Loss | Opens after AC loss ≥5 seconds |
| Auto Shutdown: Temperature | Opens when internal temp ≥70°C |
| Manual Shutdown | Emergency stop button on enclosure |
| Auto Reset | Yes — auto-closes when AC power restored |
| Switching Speed | <5ms (energy-storage spring mechanism) |
| Physical and Environmental | |
| Protection Rating | IP65 |
| Flame Retardant Rating | UL 94 V-0 (enclosure body) |
| Operating Temperature | −20°C to +50°C |
| Auto-Trip Temperature | +70°C (internal enclosure) |
| Storage Temperature | −40°C to +85°C |
| Protection Class | Class II |
| Standards and Certifications | |
| Test Standard | EN 60947-1 & 3 |
| Certifications | CE, ISO 9001, ISO 14001 |
| DC Switch Standard | IEC 60947-3 (ed.3.2):2015, UL508i, GB14048.3 |
| Utilisation Category | DC-PV0 / DC-PV1 |
| Mechanical Life | |
| Operations (total) | 10,000 |
| Operations under load (PV1) | >1,500 |
| Manufacturer | |
| Manufacturer | Projoy Electric Co., Ltd. |
Frequently Asked Questions
Related Products
Projoy Battery Isolator with Enclosure (PEBS-L)
DC MCB for battery-inverter circuits
Projoy DC Surge Protector (PESP)
SPD for DC PV string protection
