Keylock Switch Accessories

Table of Contents

1. Key Switch Basics
2. Three Common Circuit Types
3. Wiring and Safety Points
4. Keylock Switch Accessories
5. Keylock Switch Market
6. Types of Keylock Switches
7. E-Switch Keylock Switches
8. JD Series Keylock Switches
9. Keylock DSP5 Switch
10. FAQ

Key Switch Basics

The core function of a key lock switch (key switch) is to control the opening and closing of internal contacts through the rotation of a mechanical key. This enables authorized starting and stopping of the power/control circuit. Below, we will explain the basic principles, terminal definitions, and wiring steps, along with safety precautions. Follow the instructions to connect it properly.

Three Common Circuit Types

I. Key Switch Basics: Terminals and Positions

1. Core Terminals (Most Common: Pin 2/3, Pin 4)

• C (COM, Common): Power input (live wire/positive).
• NO (Normally Open): Connected to C when the key is ON; disconnected when OFF (most commonly used).
• NC (Normally Closed): Connected to C when the key is OFF; disconnected when ON (used for alarm/interlock).

2-Position Key Switch (OFF-ON): Only C + NO (pin 2), or C + NO + NC (pin 3).

3-Position Key Switch (OFF-ACC-ON): C + ACC + ON (pin 4), where ACC is auxiliary power (e.g., car audio), and ON is main power.

II. Wiring Steps

Circuit 1: DC Small Load (12V/24V, lights, fans, small motors, ≤5A) – Simplest
Applicable to: 12V batteries, 24V industrial control, access control, small equipment.
Components: Key switch (pins 2: C, NO), fuse (FUSE, 1~5A), load (light/motor), power supply.

Wiring steps: Power supply positive terminal → Fuse → Key switch C terminal.
Key switch NO terminal → Load positive terminal.
Load negative terminal → Power supply negative terminal (grounded).
Principle: When the key is turned ON, C-NO conducts, energizing the load; OFF/removing the key disconnects the power and locks the circuit.

Circuit 2: AC 220V/380V High Power (motors, equipment, >5A) – Contactor Control
Applicable to: Industrial equipment, water pumps, fans, high-power loads (key switch cannot directly carry high current).

Components: Key switch (C+NO), AC contactor (KM, coil 220V), fuse, circuit breaker, load.

Wiring (control circuit, 220V):
Live wire L → Fuse → Key switch C terminal.
Key switch NO terminal → Contactor coil A1.
Contactor coil A2 → Neutral wire N.
Main circuit: Circuit breaker → Contactor main contacts → Load (motor).

Principle: Key ON → Contactor coil energized and engaged → Main contacts closed → High-power load operates; Key OFF → Coil de-energized → Main contacts open → Load de-energized.

Circuit 3: Vehicle-mounted / 3-position Key Switch (OFF-ACC-ON) – Multi-power Control
Applicable to: Electric vehicles, forklifts, equipment with segmented power supply (ACC: audio/lighting; ON: main control/motor).

Terminal: C (Common + 12V Positive), ACC (auxiliary), ON (main power), GND (negative).

Wiring:
Battery + → Fuse → Key switch C terminal.
ACC terminal → Auxiliary load (lights, audio).
ON terminal → Main control / motor / relay coil.
All load negative terminals → Battery negative terminal (GND).
Position: OFF (all off) → ACC (auxiliary only) → ON (all on).

III. Wiring and Safety Points (Must Read)

Current Matching: The rated current of the key switch contacts is generally 3A~5A. If it exceeds 5A, a contactor/relay must be added. Directly connecting high-power loads is strictly prohibited (it will burn out the contacts).

Fuse is Required: A fuse (1.2~1.5 times larger than the load current) should be connected in series with the power input line to prevent short circuits and wire burnout.

Terminal Marking: Before wiring, check the C/NO/NC/ACC/ON markings on the switch to avoid reversing them.

Mechanical Locking: The key can only be removed in the OFF position to prevent accidental power cut-off and unauthorized operation.

Grounding / Insulation: Ensure proper insulation of AC circuits and reliable grounding of DC circuits to prevent leakage.

Keylock Switch Accessories

Key lock switch accessories are divided into five categories: core body, wiring protection, installation and fixing, high-power expansion, and auxiliary protection.

I. Core Unit

1. Key Switch Body (Select by Position/Terminal):

• 2 Positions (OFF-ON, Most Common): Pin 2 (C/COM+NO), Pin 3 (C+NO+NC); Rated Current 3A/5A, Voltage 12V/24V/220V; Hole Diameter 16mm/19mm/22mm (Standard Panel Opening).
• 3 Positions (OFF-ACC-ON, Vehicle-Mounted/Separate Positions): Pin 4 (C+ACC+ON+GND), used for branch power supply (ACC Auxiliary, ON Main Power).

Standard Configuration: 2 Keys (Universal/Interlock Optional), Mounting Nut, Flat Washer, Spring Washer.

2. Spare Key/Lock Cylinder: Same Model Spare Key (Anti-Loss), Interlock/Open Lock Cylinder (Multiple Switches Managed by Key).

II. Wiring and Protection Accessories

1. Fuse/Blow-Out Fuse: Specifications: Glass Tube Fuse/Blade Fuse, Current... 1A~30A (Select according to load, 1.2~1.5 times higher than rated).

Accessories: Fuse holder, fuse clip, illuminated fuse holder (light indicator when fuse blown).

Wiring: Connect the fuse in series with the positive power input, then connect to the C terminal of the key switch.

2. Terminal Blocks: Cold-pressed terminals: U-shaped/fork-shaped/round lugs (OT/UT), compatible with 0.5~2.5mm² wires, secure connection to prevent loosening. Terminal blocks: Centralized multi-wire connection for easy maintenance. Heat shrink tubing/insulating sleeve: Wraps the connection points to prevent short circuits and leakage.

III. High-Power Extension Accessories (>5A required, for burn-out switch contacts)

Key switch contacts are only 3~5A; for over 5A, a relay/contact must be added to control a large current with a small current. DC Relay (12V/24V): 4-pin/5-pin, coil voltage matching, contact current 10A~40A. Wiring: Key switch controls relay coil; relay main contacts control high-power loads. AC Contactor (220V/380V): Coil 220V, main contacts 10A~100A, used for high-power equipment such as motors, pumps, and fans. Relay Base/Socket: For easy plugging and unplugging and replacement.

IV. Installation and Fixing Accessories (Required, for fixing the switch)

Mounting nut + flat washer + spring washer: Fixes the switch on the panel to prevent loosening. Panel cutter: 16mm/19mm/22mm, for cutting standard mounting holes. Waterproof ring/Sealing Gasket: For outdoor/humid environments, IP54/IP65 waterproof and dustproof. Mounting Panel/Decorative Panel: Aesthetically pleasing, secures multiple switches.

V. Auxiliary Protective Accessories (Optional, enhances safety/durability)

Waterproof Junction Box: For outdoor/humid environments, protects wiring terminals. Switch Protective Cover: Prevents accidental touches and dust. Indicator Light (LED): Displays power status on the NO terminal.

Keylock Switch Market

I. Market Size and Growth (2025-2032)

Global Market: Approximately US$833 million (≈ RMB 6 billion) in 2025, with a CAGR of 3.2% from 2026 to 2032, reaching US$1.038 billion in 2032.

China Market: Approximately RMB 4.8 billion in 2025, with a CAGR of 8.4% from 2025 to 2030, projected to reach RMB 7.2 billion in 2030, a growth rate higher than the global average (driven by smart manufacturing, new energy, charging piles, and industrial control security).

Core Drivers: Industrial safety compliance, equipment access control, demand from new energy/charging piles/construction machinery/rail transit, and essential needs in outdoor/waterproof/high-protection scenarios; Substitution Pressure: Electronic password/fingerprint/software access control solutions, but mechanical key locks remain irreplaceable due to their absolute reliability, usability when power is off, prevention of accidental activation, and low cost.

II. Product Classification and Price Range (2026 Spot Stock)

1. By Pin Position/Terminal (Core Selection Required)

2-Pin (OFF-ON, 2-Pin/3-Pin): Most universal, industrial control/equipment/electric vehicles/distribution boxes; Price: Domestic low-end 1.5~8 RMB, mid-range (Tianyi/Yijia) 10~25 RMB, imported (APEM/Eaton) 50~200 RMB.

3-Pin (OFF-ACC-ON, 4-Pin): Vehicle-mounted/construction machinery/branch power supply; Price: Domestic 15~35 RMB, imported 80~300 RMB.

Multi-Pin/Interlock/Safety Type: Industrial safety interlocks, elevators, high-voltage equipment; Price: Domestic 50~200 RMB, imported (Castell/Siemens) 300~1500 RMB.

III. Industry Chain and Competitive Landscape

1. Upstream (Raw Materials): Copper alloy contacts, zinc alloy/stainless steel lock cylinders, engineering plastics, springs/pins, terminals/cables; Cost breakdown: Materials 60%, Processing 25%, Distribution channels 15%.

2. Major Brands (Clearly Tiered): Imported High-End (High Reliability/Military/High-End Industrial Control): APEM, Eaton, Siemens, RAFI, Castell, Omron—High price, long lifespan, comprehensive certifications (CE/UL/CSA), gross profit margin 40%-55%.

Domestic Mid-Range (Industrial Control/New Energy/Mainstream Equipment): Shanghai Tianyi (TAYEE), Yijia, Hongbo, Hangzhou Sanli, Chint, Delixi—High cost-performance ratio, fast delivery, compatible with domestic standards, gross profit margin 25%-35%. Domestic low-end (electric vehicles/small appliances/low-end server racks): Small and medium-sized factories in Wenzhou/Dongguan, white-label products—extremely low prices (1.5~8 RMB), homogeneous, price wars, gross profit margin 10%-20%.

3. Competitive Characteristics: Low-end red ocean: Fierce price wars, homogeneous products, low gross profit, concentrated in Wenzhou, Dongguan, and Taizhou. Mid-to-high-end blue ocean: Competition based on protection level (IP65+), mechanical life (≥100,000 cycles), certification, customization, waterproof/vibration-resistant/temperature-resistant, accelerated domestic substitution.

IV. Core Trends (2026-2030)

High Reliability + High Protection: IP65/IP67 waterproof and dustproof, -40℃~85℃ wide temperature range, vibration resistance/pry resistance, and long lifespan (≥100,000 cycles) are becoming standard features.

Mechatronics Integration (Smart Key Locks): Mechanical keys + electronic chips/encoding, status feedback, LED indicators, anti-copying, and network authorization, adapting to IoT/industrial interconnection, increasing penetration in high-end scenarios.

Customization/Modularization: Multi-position, interlocking, dual-path control, special hole diameters/wiring, and compatibility with equipment panels to meet specific scenarios.

Accelerated Domestic Substitution: The import share in the mid-to-high-end market is declining, while domestic mid-range brands (Tianyi, Yijia, etc.) are seizing the industrial control/new energy/charging pile market.

Stricter Compliance: CE, UL, CCC, and industrial safety standards are being raised, eliminating low-quality products.

Types of Keylock Switches

Key Lock Switches: All Types Classified

I. Classification by Position (Most Common)

Two Positions (OFF → ON): Power off when the key is removed, power on when the key is turned on.
Applications: Equipment power supplies, cabinets, charging piles, machines. Best-selling and most universal.

Three Positions (OFF → ACC → ON): Two-stage power supply: auxiliary power + main power.
Applications: Forklifts, construction vehicles, electric vehicles, agricultural machinery.

Self-Resetting Key Switch: Power on when the key is turned on, automatically returns to its original position when released. Only provides a start signal, not continuous power.
Applications: Equipment start-up, motor start-up, ignition start.

Multiple Positions (4-6 positions): Multi-level switching, position selection.
Applications: Instruments, machine tools, industrial control.

II. Classification by Pins/Contacts

2 Pins (Single Group, Single Switch): Simplest, one-way switching.

3 Pins (Normally Open + Normally Closed): COM / NO / NC. Can be used for control, alarm, interlocking.

4 Pins / 6 Pins Foot (Dual-Circuit Control): Dual-Group Synchronous Switch, simultaneous on/off of two circuits, commonly used in safety equipment, with locking contacts, dual-circuit safety type, industrial safety, elevators, high-voltage equipment.

III. Classification by Mounting Hole Diameter

16mm Mini type, small equipment, cabinet.
19mm Universal type, electric vehicles, instruments.
22mm Industrial standard, same as push-button switches, industrial control computers, machine tools. These three are globally universal sizes.

IV. Classification by Housing Material

Plastic housing: Inexpensive, household, small appliances, low-end equipment.
Zinc alloy metal housing: Wear-resistant, pry-proof, industrial, outdoor, mainstream.
All stainless steel: Corrosion-resistant, high-end equipment, outdoor waterproof.

V. Classification by Waterproof Rating

Standard type (IP40): Indoor, cabinet, dry environment.
Waterproof type (IP54 / IP65): Outdoor, rain, forklifts, charging piles, mechanical equipment.
Dustproof and corrosion-resistant type: Harsh industrial environment.

VI. Classification by Key Structure

Standard key (opens multiple keys/misaligned keys): One key opens multiple keys/Each lock has an independent key; anti-copying key; irregularly shaped slot, anti-theft, high-end equipment; combination key lock, chip key; smart lock with encryption.

VII. By Function

Power switch lock (most commonly used); cabinet door lock (short lock cylinder); elevator safety lock; equipment access lock; charging gun lock, new energy lock; machine tool/automation control lock.

E-Switch Keylock Switches

E-Switch (Ise, USA)'s core key lock switches are the KO series, primarily targeting industrial, equipment, security, and automotive applications. Their key advantages include panel mounting, multiple position settings, high reliability, and UL/CE certification. Below, we'll provide a comprehensive overview from the perspectives of series, models, specifications, selection, applications, and procurement.

I. Core Series: KO Series (The Only Mainstream Key Lock Series)

1. Basic Positioning

Brand: E-Switch (USA), Industrial Grade Electromechanical Switch, RoHS/REACH Compliant, UL/CE Certified.

Mounting Hole Diameter: 12mm / 19mm (Standard Panel Opening).

Positions: 2 Positions (OFF-ON), 3 Positions (OFF-ACC-ON), Momentary Reset, Multi-Position.

Contacts: Silver Alloy, Mechanical Life ≥ 40,000 Cycles, Electrical Life ≥ 6,000 Cycles.

Rated: 1A/125VAC, 0.5A/250VAC, 4A/125VAC (by Model).

Keys: Flat/Cylindrical Key, All-in/Individual Key, Anti-Pull (Key can only be removed from the OFF position).

II. Core Specifications

Table: Item Standard Value
Mounting Hole Diameter: 12mm / 19mm
Positions: 2 Positions (OFF-ON), 3 Positions (OFF-ACC-ON), Momentary Reset
Contact Configuration: SPST (Single-pole single-throw), SPDT (single-pole double-throw), SP3T (single-pole triple-throw)
Rated current: 1A@125VAC; 4A@125VAC; 0.5A@250VAC
Operating temperature: -40℃ ~ +85℃
Protection: IP40 (standard), IP65 can be customized
Terminals: Solder lug, screw terminal
Key removal: OFF position only (safety type) / any position.

III. Common Model Overview (2026 in Stock)

(1) 2-position basic type (OFF-ON, most commonly used)
KO103A102: 12mm, SPST, 1A/125VAC, solder lug, key removal OFF only → Industrial control / cabinet power supply.
KO106A102: 19mm, SPST, 1A/125VAC, solder lug → Equipment / charging pile / Security.
KO128B2007: 19mm, SPST, 4A/125VAC, screw terminal → High current / motor control.

(2) 3-position type (OFF-ACC-ON, vehicle / construction machinery)
KO130E: 19mm, SP3T, 4A/125VAC, 3 positions, key only OFF pull → forklift / construction vehicle / agricultural machinery.
KO133C801: 19mm, SPDT, 1A/125VAC, 3 positions, self-reset → start signal / ignition.

(3) Self-reset / momentary type
KO130AA126: 19mm, 3-position self-reset, screw to ON and release to spring back → equipment start / motor control.

IV. Model Naming Rules

KO 103 A 102 → Disassembly:
KO: Series code (key lock)
103: Hole diameter / Dimensions (103=12mm; 128/130/133=19mm).

A/B/C: Contacts/Positions (A=2-position SPST; C=2-position SPDT; E=3-position SP3T).

102/2007/801: Terminals/Keys/Removable Lock Positions (102 = Solder tab, OFF only; 2007 = Screw terminal).

V. Core Advantages and Application Scenarios

1. Core Advantages
Industrial-grade reliability: Silver contacts, wide temperature range, vibration resistant, suitable for long-term power supply/frequent operation.
Safe authorization: Physical key isolation, prevents accidental touch and unauthorized start, meets industrial control/electrical safety standards.
Standard compatibility: 12/19mm opening, adapts to standard panels, easy replacement.
Complete certifications: UL, CE, RoHS, suitable for export/high-end equipment.

2. Typical Applications
Industry: PLC Control cabinets, machine tools, automation equipment, testing instruments.
Transportation: Electric vehicles, forklifts, construction machinery, agricultural machinery, vehicle-mounted equipment.
New Energy: Charging piles, photovoltaic/energy storage cabinets, distribution boxes.
Security: Access control, cabinets, security mainframes, self-service terminals.
Medical/Equipment: Medical instruments, self-service equipment, elevator control.

Keylock DSP5 Switch

The DSP5 key lock switch is not a standard industrial model; it's a 5-position key lock specifically designed for Duramax diesel vehicles' EFI Live DSP5 tuning. Its core features include 5 rotation positions, key withdrawal only at positions 1, 3, and 5, and resistance signal switching for ECM tuning modes. Below, we'll thoroughly explain its definition, core parameters, model, wiring, Digikey replacement, and selection.

I. Core Definition and Applications

DSP5 = Digital Switch Position 5: A 5-position digital switch that, in conjunction with EFI Live software, allows the ECM to store 5 power mode settings (Stock/Tow/Street/Hot/Race). It enables key rotation switching and physical locking to prevent accidental activation/unauthorized switching.

Brand: Fish Tuning (original factory customized), not the APEM/E-Switch standard series; Digikey does not have original DSP5 stock, only a 5-position industrial key lock of the same specification as a substitute.

Core Scenarios: GM Duramax diesel pickup trucks (LB7/LLY/LBZ/LMM/LML), Ford diesel vehicles, used for power mode locking, preventing child/unauthorized adjustments, and compliant locking.

II. DSP5 Key Lock Core Parameters

Positions: 5-position self-locking (Maintained), 45° rotation/position, total swing angle 180°.

Position 1: Stock/Valet (Original Factory/Valet).

Position 2: Tow.

Position 3: Street.

Position 4: Hot.

Position 5: Race (Racing/Maximum Power).

Key Removal: Only positions 1, 3, and 5 are removable (safety lock), positions 2 and 4 are not removable (prevents accidental removal and power failure).

Electrical: Resistive signal switch (not power on/off), outputs 5 sets of fixed resistance values (1k/1.8k/3.3k/10k/open circuit), connects to ECM B15 pin, 12V vehicle low voltage, low current (≤100mA).

Lock Cylinder: 4-pin anti-theft, standard configuration includes 2 brass keys (general opening/individual optional).

Installation: 19mm panel opening (standard industrial aperture, compatible with APEM JD/LK, E-Switch KO).

Terminals: 2 wires (signal + ground), pre-wired/soldered.

Protection: IP40, operating temperature -30~85℃.

III. Original Models (Fish Tuning, by Vehicle Model)

FTKeyLB7: Compatible with 2001-2004 LB7 Duramax.

FTKeyLLY: Compatible with 2004.5-2005 LLY.

FTKeyLBZ/LMM: Compatible with 2006-2010 LBZ/LMM.

FTKeyLML: Compatible with 2011-2016 LML.

FTKeyFordU: Ford Universal Version.

IV. Digikey 5-Digit Key Lock Alternative Solution

Digikey does not have an original DSP5, but it offers 5-digit, 19mm, removable and customizable industrial key locks with resistor compatibility, providing a perfect alternative. The following are precise selection options:

1. Preferred Alternative (APEM LK series, most compatible with 19mm, 4 pins, 45°):
Model: LK98NB126N3 (Digikey in stock)
5 Self-locking, 45°/position, 19mm opening, solder pad terminals.
Key removable: Customizable for 1, 3, or 5-position removability (compatible with DSP5).
Contacts: DP5T (double-pole 5-throw), can be connected to a resistor network to simulate DSP5 signals.
Rated: 4A@125VAC, UL/CE, industrial-grade reliability.
Advantages: Same hole diameter, same lock cylinder, same swing angle; directly replaces the panel opening; only requires external resistors (1k/1.8k/3.3k/10k) to achieve DSP5 functionality.

2. High-performance alternative (E-Switch KO series):
Model: KO130F (5-position, 19mm, SP5T, solder pad, customizable key removability).
Suitable for budget-conscious scenarios requiring only basic 5-position switching.

3. Precision 5-position alternative (Grayhill 58J series, Digikey):
Model: 58J8A36-01-2-05N.
5 positions, 36°/position, 19mm, DP5T, gold contacts, anti-static.
Suitable for high-precision resistance signals and harsh automotive environments.

V. DSP5 Function Implementation

Resistor Configuration (Standard DSP5 Signal, ECM Recognition):
Position 1: Open Circuit (5V) → Stock.
Position 2: 10kΩ → Tow.
Position 3: 3.3kΩ → Street.
Position 4: 1.8kΩ → Hot.
Position 5: 1kΩ → Race.

Wiring:
Switch Common Terminal (COM) → ECM B15 (C2 blue plug).
Switch Positions → Corresponding Resistor → Ground.

Key Lock: Only positions 1/3/5 are pulled to lock the current mode.

VI. Selection & Procurement Recommendations

Original DSP5: Only available from Fish Tuning/Tuners, not available from Digikey/Mouser, unit price... $60-70, currently clearing inventory after discontinuation.

Digikey Alternative: APEM LK98NB126N3 preferred, 19mm, 5-position, customizable key pull position, industrial-grade durability, $10-15 per unit, ample stock.

Key Confirmations: Key pull position (1/3/5), 19mm opening, 5-position self-locking, resistor signal compatibility.

FAQ