V23109-S2421-D020 | Vincotech | 4PDT · 20V DC · 4A | New Original

Part Number: V23109-S2421-D020 | Alt. Reference: V23109S2421D020 | Manufacturer: Vincotech / Tyco Electronics | Condition: New Original

Know Exactly What You Are Ordering

The V23109-S2421-D020 is a PCB-mount power relay from the Vincotech V23109 series — a long-established family of miniature multi-pole relays widely used in industrial control panels, energy meters, medical equipment, building automation, and telecommunications infrastructure.

Decoding the part number removes all ambiguity:

Segment	Meaning
V23109	Vincotech / TE Connectivity relay series identifier
S	PCB solder-pin termination (through-hole)
2	4-pole (4PDT) contact configuration
4	Contact rating group
2	Contact material variant
1	Coil voltage group
D020	Coil voltage: 20 V DC

Bottom line: this is a 4-pole double-throw (4PDT), 20 V DC coil, PCB through-hole relay. Four independent changeover contacts, all switching simultaneously from a single 20 V DC coil.

Technical Specifications

Parameter	Value
Part Number	V23109-S2421-D020
Manufacturer	Vincotech / TE Connectivity
Series	V23109
Relay Type	PCB power relay (through-hole solder pins)
Contact Configuration	4PDT (4 × changeover / Form C)
Contact Rated Voltage	250 V AC / 30 V DC
Contact Rated Current	4 A per contact
Switching Power (max.)	1,000 VA (AC) / 120 W (DC)
Coil Voltage (nominal)	20 V DC
Coil Resistance (nominal)	Approx. 400–500 Ω (20 V DC type)
Coil Power Consumption	Approx. 0.8–1.0 W
Pick-up Voltage	≤ 15 V DC (75% of nominal)
Drop-out Voltage	≥ 2 V DC
Operate Time	Approx. 10 ms
Release Time	Approx. 5 ms
Mechanical Life	≥ 10,000,000 operations
Electrical Life	≥ 100,000 operations (at rated load)
Insulation Voltage	4 kV (coil to contacts)
Operating Temperature	−40 °C to +70 °C
Mounting	PCB through-hole (2.54 mm / 5.08 mm pin grid)
Standards	IEC 61810, VDE, UL, CSA
Condition	New, original OEM

Note: Always verify coil resistance with a multimeter before installation. The 20 V DC nominal coil requires a stable 20 V DC supply — do not operate on 24 V DC without verifying the coil's voltage tolerance range, as sustained overvoltage will overheat and damage the coil.

Why 4PDT? Understanding the Contact Configuration

Most relays used in simple on/off switching are SPDT (1 pole) or DPDT (2 poles). The V23109-S2421-D020 offers 4 independent changeover contacts — four poles, each with a common (COM), normally open (NO), and normally closed (NC) terminal.

This matters when the application needs to:

Switch multiple independent circuits simultaneously with a single coil energisation
Maintain signal circuit isolation — for example, switching four separate low-voltage signal lines without inter-channel interaction
Implement interlocking logic where one relay action must simultaneously change the state of multiple circuit paths
Replace a bank of separate single-pole relays with one compact 4-pole device

Each of the four contacts is electrically independent from the others. Rated at 4 A / 250 V AC per contact, they are suitable for both signal-level and light power switching duties.

Three Ways This Relay Is Typically Used

① Control Panel Signal Switching In industrial control panels built to IEC 60204 or equivalent, the V23109 series relays are used as intermediate relays between PLC output cards (which output low-current 24 V DC signals) and higher-current field loads. A single 4PDT relay allows one PLC output to simultaneously control up to four separate switching functions — indicator lights, contactors, signal lines, and safety circuits — without loading the PLC output.

② Energy Meter and Tariff Switching The V23109 series has a long history of use in electronic energy meters, tariff change-over units, and prepayment meter platforms. The 4PDT configuration enables simultaneous switching of multiple metering circuits, pulse outputs, and communication lines with a single relay actuation.

③ Building Automation and HVAC Systems Building management systems use multi-pole PCB relays to switch heating, ventilation, and access control outputs. The compact PCB footprint of the V23109 allows dense relay board layouts in DDC (Direct Digital Control) panels.

PCB Footprint and Soldering Notes

The V23109-S2421-D020 uses through-hole (THT) solder pins arranged on a standard grid. Key mechanical points for PCB designers and repair technicians:

Pin pitch follows the V23109 series standard — consult the series datasheet for exact pin coordinates and recommended PCB pad dimensions
The relay body height must be verified against the clearance available in the target assembly
Reflow soldering is not applicable — this is a through-hole component soldered by wave soldering or hand soldering
Recommended solder: Sn63/Pb37 or SAC305 lead-free; soldering temperature 260 °C maximum at the pin for ≤5 seconds
After soldering, avoid mechanical stress on the pins during handling — the coil and contact spring mechanism is sensitive to impact

V23109 Series — Coil Voltage Variants at a Glance

If the 20 V DC coil does not match your supply voltage, the V23109 series covers a range of standard coil voltages:

Part Number Suffix	Coil Voltage
D005	5 V DC
D006	6 V DC
D012	12 V DC
D015	15 V DC
D020	20 V DC ← this product
D024	24 V DC
D048	48 V DC

Most common substitution question: "Can I use the D024 (24 V DC) version instead of the D020?" Strictly, no — the coil resistance, pick-up voltage, and thermal characteristics are specified for the nominal coil voltage. Running a 20 V coil on a 24 V supply increases coil dissipation by 44% (power scales with V²), which will reduce coil life and may cause overheating. If your supply is 24 V DC, specify the D024 variant.

Genuine OEM vs Generic PCB Relays

At $15, the V23109-S2421-D020 sits in a price range where generic substitutes are widely offered. For many non-critical applications, this may be acceptable. For applications where relay performance affects safety, measurement accuracy, or equipment certification, the OEM part matters:

Factor	V23109-S2421-D020 (OEM Siemens/TE)	Generic PCB Relay
Contact material specified	✅ Silver-alloy, characterised	❌ Often unspecified
Coil voltage tolerance tested	✅ Pick-up ≤75% Vnom guaranteed	❌ Often unverified
Mechanical life	≥10,000,000 cycles, tested	❓ Claimed, unverified
Electrical life	≥100,000 at rated load	❓ Often lower
Insulation voltage (coil-contact)	4 kV, certified	❓ Often not tested
UL / VDE listing	✅	❌ Rarely
PCB pin dimensions	✅ Exact standard	⚠️ May differ — fitment risk
CE documentation	✅	❌

For CE-marked equipment, metering systems under MID (Measuring Instruments Directive), or any application requiring component traceability, the genuine OEM part is required.

Ordering & Delivery

✅ New Original — genuine Vincotech / TE Connectivity V23109 series unit
✅ In Stock — dispatches within 1–3 working days
✅ Global Shipping — DHL / FedEx / UPS with tracking
✅ Volume pricing available — ideal for PCB assembly batches and maintenance stock
✅ Anti-static packaging — ESD-safe for PCB-mount components

Frequently Asked Questions

Q1: What does "4PDT" mean, and how many contacts does this relay have?

4PDT stands for 4-Pole Double-Throw. The relay has four independent switching contacts, each with three terminals: Common (COM), Normally Open (NO), and Normally Closed (NC). When the coil is de-energised, each COM is connected to its NC terminal. When the coil is energised with 20 V DC, all four COMs simultaneously switch to their NO terminals. The four contact poles are electrically isolated from each other and from the coil circuit. In total the relay has 4 × 3 = 12 contact terminals plus 2 coil terminals.

Q2: The coil voltage is 20 V DC. Can this relay be driven from a 24 V DC PLC output? Not directly without precautions. The nominal coil voltage is 20 V DC, and the coil is specified for operation at that voltage. Applying 24 V DC continuously increases coil power dissipation by approximately 44% above the rated value (power = V²/R), which will shorten coil life and may cause the relay to run excessively hot, particularly in high-ambient-temperature installations. If your control supply is 24 V DC, the correct variant is the V23109-S2421-D024. However, if the 24 V supply in your system is well-regulated and the application is low-duty-cycle (relay energised only briefly), the thermal impact is reduced — assess carefully for your specific duty cycle and ambient conditions.

Q3: What is the contact rating, and can this relay switch 230 V AC mains circuits?

The contacts are rated at 4 A / 250 V AC per pole. This means each contact is suitable for switching 230 V AC (standard European mains voltage) at up to 4 A — equivalent to approximately 900 W resistive load per contact. For inductive loads (motors, solenoids, transformers), derate appropriately as inductive switching causes higher peak currents and arcing. Always verify that the load current does not exceed 4 A and that the load voltage does not exceed 250 V AC per contact.

Q4: Is the V23109-S2421-D020 a PCB relay or a panel-mount relay? Does it need a socket?

This is a PCB through-hole relay — it is designed to be soldered directly onto a printed circuit board. It does not use a plug-in socket. If you are looking for a panel-mount or DIN-rail relay with a socket base (for screwdriver-replaceable relays in control cabinets), you need a different product series. The V23109 PCB relay is used in embedded electronics and PCB assemblies, not in socket-based industrial relay panels.

Q5: What is the difference between V23109-S2421-D020 and V23109S2421D020?

These are the same part number. V23109S2421D020 is simply the hyphen-free version, often used in ERP systems, component databases, and purchasing platforms that do not support hyphens in part number fields. Both designations refer to the identical component.

Q6: What coil resistance should I measure if I test this relay with a multimeter?

For a 20 V DC nominal coil, the coil resistance of the V23109 series is approximately 400–500 Ω. This gives a coil current of around 40–50 mA and a coil power dissipation of approximately 0.8–1.0 W at nominal voltage. If you measure significantly lower resistance (e.g. < 200 Ω), the coil may have an internal short. If you measure open circuit (∞), the coil winding has failed. These checks are useful for diagnosing a suspect relay before installation.

Q7: How do I identify the coil pins and contact pins on the PCB footprint?

The V23109 series follows a standard pin numbering convention as published in the Siemens / TE Connectivity datasheet for this series. Coil pins are typically labelled A1 and A2 (or pins 1 and 2 in some footprint notations). Contact pins follow the pole numbering. The relay body has a notch or chamfer on one corner for orientation reference, which corresponds to pin 1 in the datasheet footprint. Always refer to the official V23109 series datasheet (available from TE Connectivity's component library) for the authoritative pin diagram before designing or reworking a PCB.

Q8: Can I use this relay in a safety relay circuit (e.g. SIL 2, Category 3)?

The V23109-S2421-D020 is a general-purpose PCB relay. Its suitability for use in a safety function depends on the complete safety system architecture, the required Safety Integrity Level (SIL) or Performance Level (PL), the relay's published MTTF_d data, and whether forced-guided contact operation is required. Standard V23109 relays do not have forced-guided (positively guided) contacts — if your safety application requires contact mirror function or forced-guided contacts as per IEC 61810-3, you need a relay specifically designed and certified for safety circuits. Consult your safety system designer or the relevant machinery directive / functional safety standard for your application.

Q9: Is this item new or from surplus stock?

This is a new, original component. It is not surplus, not used, not pull-out from equipment, and not repackaged. The relay contacts and coil are in as-manufactured condition.

Q10: Do you offer volume pricing for larger quantities?

Yes. PCB relay orders in quantities of 10 units or more qualify for volume pricing. Contact us with your required quantity and delivery address for a prompt quotation. We regularly supply batches for PCB assembly production runs and maintenance spare parts kits.

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