IDEC RU Series Universal Relays
Full-featured universal miniature relays designed with environmental considerations.
Note: See website for details on approvals and standards. Lloyd Register type approved.
Key Features
Safety: Contact position visible through five small windows. Latching lever allows operation checking without energizing the coil. Latching lever color-coded: AC coils (Orange), DC coils (Green). Non-polarized LED indicator available on plug-in relays.
Reliability: Simple construction with no internal wires.
Ease of Use: Marking plate for easy relay identification (optional plates available in four colors). Applicable for small loads to maximum contact currents.
Product Overview
The IDEC RU Series offers a comprehensive range of universal miniature relays designed for robust performance in various industrial environments. These relays are available in DPDT (RU2) and 4PDT (RU4, RU42) configurations, with options for plug-in and PCB terminals, and various coil voltage and protection circuit configurations.
Specifications
Coil Ratings
| Rated Voltage (V) | Coil Voltage Code | Rated Current (mA) ±15% (at 20°C) 50 Hz / 60 Hz | Coil Resistance (Ω) ±10% (at 20°C) | Operating Characteristics (against rated values at 20°C) Maximum Continuous Applied Voltage | Minimum Pickup Voltage | Dropout Voltage | |
|---|---|---|---|---|---|---|---|
| AC (50/60 Hz) | 24 | A24 | 49.3 / 42.5 | 164 | 110% | 80% maximum | 30% minimum |
| 100-110 | A100 | 9.2-11.0 / 7.8-9.0 | 3,460 | ||||
| 110-120 | A110 | 8.4-10.0 / 7.1-8.2 | 4,550 | ||||
| 200-220 | A200 | 4.6-5.5 / 4.0-4.6 | 14,080 | ||||
| 220-240 | A220 | 4.2-5.0 / 3.6-4.2 | 18,230 | ||||
| DC | 6 | D6 | 155 | 40 | 110% | 80% maximum | 10% minimum |
| 12 | D12 | 80 | 160 | ||||
| 24 | D24 | 44.7 | 605 | ||||
| 48 | D48 | 18 | 2,560 | ||||
| 100 | D100 | 9.7 | 10,000 | ||||
| 110 | D110 | 8.9 | 12,100 |
Note: The rated current includes the current draw by the LED indicator.
Contact Ratings
| Model | Contact | Continuous Current | Allowable Contact Power | Rated Load | Voltage (V) | Ind. Load | Res. Load | Electrical Life (operations) | Contact Material |
|---|---|---|---|---|---|---|---|---|---|
| DPDT (RU2) | 10A | 2500VA AC / 300W DC | Resistive Load | 250 AC | 5A | 10A | 100,000 min. | Silver alloy | |
| 5A | 1250VA AC / 150W DC | Inductive Load | 30 DC | 2.5A | 5A | 500,000 min. | |||
| 110 DC | 0.6A | 2.5A | 300,000 min. | ||||||
| 4PDT (RU4) | 6A | 1500VA AC / 180W DC | Resistive Load | 250 AC | 2.6A | 6A | 50,000 min. | Silver (gold clad) | |
| 2.7A | 600VA AC / 90W DC | Inductive Load | 30 DC | 1.5A | 3A | 200,000 min. | |||
| 110 DC | 0.4A | 0.8A | 100,000 min. | ||||||
| 4PDT (RU42) bifurcated | 3A | 750VA AC / 90W DC | Resistive Load | 250 AC | 0.8A | 3A | 100,000 min. | Silver-nickel (gold clad) | |
| 0.44A | 200VA AC / 45W DC | Inductive Load | 30 DC | 1.5A | 3A | 100,000 min. | |||
| 110 DC | 0.22A | 0.8A | 100,000 min. |
Note: On 4PDT relays, the maximum allowable total current of neighboring two poles is 6A. At the rated load, ensure the total current of neighboring two poles does not exceed 6A (3A + 3A = 6A).
Specifications
| Model | Contact Resistance (*1) | Minimum Applicable Load (*2) (reference value) | Operate Time (*3) | Release Time (*3) | Power Consumption | Insulation Resistance | Dielectric Strength | Operating Frequency | Vibration Resistance | Shock Resistance | Mechanical Life | Electrical Life | Operating Temperature (*4) | Operating Humidity | Storage Temperature | Storage Humidity | Weight (Approx.) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| RU2 (DPDT) | 50 mΩ maximum | 24V DC, 5 mA / 1V DC, 1 mA / 1V DC, 0.1 mA | 20 ms maximum | 20 ms maximum | AC: 1.1-1.4VA (50 Hz), 0.9-1.2VA (60 Hz) DC: 0.9-1.0W | 100 MΩ minimum (500V DC megger) | Between contact and coil: 2500V AC, 1 minute Between contacts of different poles: 2500V AC, 1 minute Between contacts of the same pole: 1000V AC, 1 minute | Electrical: 1800 ops/h max. Mechanical: 18,000 ops/h max. | Damage limits: 10-55 Hz, 0.5 mm amplitude Operating extremes: 10-55 Hz, 0.5 mm amplitude | Damage limits: 1000 m/s² Operating extremes: 150 m/s² | AC: 50,000,000 ops DC: 100,000,000 ops | See H-019 and H-021. | PCB terminal: -55 to +70°C (no freezing) Others: -55 to +60°C (no freezing) | 5 to 85% RH (no condensation) | -55 to +70°C RH (no freezing) | 5 to 85% RH (no condensation) | 35g |
| RU4 (4PDT) | 50 mΩ maximum | 24V DC, 5 mA / 1V DC, 1 mA / 1V DC, 0.1 mA | 20 ms maximum | 20 ms maximum | AC: 1.1-1.4VA (50 Hz), 0.9-1.2VA (60 Hz) DC: 0.9-1.0W | 100 MΩ minimum (500V DC megger) | Between contact and coil: 2500V AC, 1 minute Between contacts of different poles: 2000V AC, 1 minute Between contacts of the same pole: 1000V AC, 1 minute | Electrical: 1800 ops/h max. Mechanical: 18,000 ops/h max. | Damage limits: 10-55 Hz, 0.5 mm amplitude Operating extremes: 10-55 Hz, 0.5 mm amplitude | Damage limits: 1000 m/s² Operating extremes: 150 m/s² | 50,000,000 ops | See H-019 and H-021. | PCB terminal: -55 to +70°C (no freezing) Others: -55 to +60°C (no freezing) | 5 to 85% RH (no condensation) | -55 to +70°C RH (no freezing) | 5 to 85% RH (no condensation) | 35g |
| RU42 (4PDT) | 50 mΩ maximum | 24V DC, 5 mA / 1V DC, 1 mA / 1V DC, 0.1 mA | 20 ms maximum | 20 ms maximum | AC: 1.1-1.4VA (50 Hz), 0.9-1.2VA (60 Hz) DC: 0.9-1.0W | 100 MΩ minimum (500V DC megger) | Between contact and coil: 2500V AC, 1 minute Between contacts of different poles: 2000V AC, 1 minute Between contacts of the same pole: 1000V AC, 1 minute | Electrical: 1800 ops/h max. Mechanical: 18,000 ops/h max. | Damage limits: 10-55 Hz, 0.5 mm amplitude Operating extremes: 10-55 Hz, 0.5 mm amplitude | Damage limits: 1000 m/s² Operating extremes: 150 m/s² | 50,000,000 ops | See H-019 and H-021. | PCB terminal: -55 to +70°C (no freezing) Others: -55 to +60°C (no freezing) | 5 to 85% RH (no condensation) | -55 to +70°C RH (no freezing) | 5 to 85% RH (no condensation) | 35g |
Notes: *1) Measured using 5V DC, 1A voltage drop method. *2) Measured at operating frequency of 120 operations/min (failure rate level P, reference value). *3) Measured at the rated voltage (at 20°C), excluding contact bouncing; Release time of AC relays with RC: 25 ms maximum. Release time of DC relays with diode: 40 ms maximum. *4) Measured at the rated voltage.
UL and c-UL Ratings
| Rating Type | RU2 | RU4 | RU42 |
|---|---|---|---|
| Resistive | 250V AC, 10A | 6A | 3A |
| General Use | -- | 6A | 3A |
| Horse Power Rating | 1/10HP | -- | -- |
| 30V DC | 10A | 6A | 3A |
CSA Ratings
| Rating Type | RU2 | RU4 | RU42 |
|---|---|---|---|
| Resistive | 250V AC, 10A | 6A | 3A |
| 30V DC | 10A | 6A | 3A |
TÜV Ratings
| Rating Type | RU2 | RU4 | RU42 |
|---|---|---|---|
| Resistive | 250V AC, 10A | 6A | 3A |
| 30V DC | 10A | 6A | 3A |
| Inductive | 250V AC, 5A | 0.8A | 0.8A |
| 30V DC | 5A | 1.5A | 1.5A |
Surge Suppressor Ratings
| Type | Ratings |
|---|---|
| RC series circuit | R: 20 kΩ, C: 0.033 µF |
| Diode | Diode reverse voltage: 1000V Diode forward current: 1A |
Product Dimensions and Connections
RU2 (DPDT Contact)
RU2 Internal Connection (Bottom View)
RU2S-* Standard: Terminals (1)12, (4)42, (5)14, (8)44, (9)11, (12)41, (13)A1, (14)A2.
RU2S-*D With Diode: Terminals (1)12, (4)42, (5)14, (8)44, (9)11, (12)41, (13)A1, (14)A2. For over 24V DC.
RU2S-*D1 With Diode Reverse Polarity Coil: Terminals (1)12, (4)42, (5)14, (8)44, (9)11, (12)41, (13)A1, (14)A2. For 24V DC.
RU2S-*R With RC: Terminals (1)12, (4)42, (5)14, (8)44, (9)11, (12)41, (13)A1, (14)A2. For over 24V DC.
RU2S-NF-*/RU2V-NF-*: Terminals (1)12, (4)42, (5)14, (8)44, (9)11, (12)41, (13)A1, (14)A2. For 24V DC or less.
RU4 (4PDT Contact)
RU4 Internal Connection (Bottom View)
RU4S-*/RU42S-* Standard: Terminals (1)12, (2)22, (3)32, (4)42, (5)14, (6)24, (7)34, (8)44, (9)11, (10)21, (11)31, (12)41, (13)A1, (14)A2. For over 24V AC/DC.
RU4S-D/RU42S-D With Diode: Terminals as above. For over 24V DC.
RU4S-D1/RU42S-D1 With Diode Reverse Polarity Coil: Terminals as above. For 24V DC.
RU4S-R/RU42S-R With RC: Terminals as above. For 24V AC/DC or less.
RU4S-NF-*/RU4V-NF-* / RU42S-NF-*/RU42V-NF-*: Terminals as above. For 24V DC or less.
Electrical Characteristics
Electrical Life Curves
Graphs illustrate the relationship between load current and electrical life (in 10,000 operations) for RU2, RU4, and RU42 relays under resistive and inductive load conditions at various voltages (250V AC, 30V DC, 110V DC). Curves show expected life based on load current.
Maximum Switching Current
Graphs show the maximum switching current (A) versus load voltage (V) for RU2, RU4, and RU42 relays under AC resistive, AC inductive (cos Ø = 0.3), DC resistive, and DC inductive (L/R = 7 ms) conditions.
Ambient Temperature vs. Temperature Rise Curves
These curves display the temperature rise (in °C) of the coil versus ambient temperature (in °C) for RU2 and RU4/RU42 relays. They show characteristics when 100% of the rated coil voltage is applied, considering different load currents (e.g., 10A x 2 poles, 5A x 2 poles, no load current). The heat resistance of the coil is 120°C.
Applicable Sockets and Accessories
Applicable Sockets
| Relay | Wiring Style | Shape | Part No. | Rated Current | Style | Applicable Spring | Hold-down Spring | Wire Spring |
|---|---|---|---|---|---|---|---|---|
| RU2 | Front Wiring Socket (*2) | SM2S-05B | 7A | Standard | SFA-202 | SFA-101 | -- | |
| SM2S-05C (*1) | 7A (UL: 10A) | Finger-safe | SFA-503 | -- | -- | |||
| SN2S-05D | 10A | Standard | -- | -- | SU9Z-S21R | |||
| SM2S-05DF (*1) | 10A | Finger-safe | SFA-301 | SY4S-51F1 | -- | |||
| SU2S-21L | 12A | Push-in (*3) | SFA-302 | -- | -- | |||
| Solder | SM2S-51 | 10A | Solder | -- | -- | -- | ||
| Rear Wiring Socket | SM2S-61 | 10A | PC board | SFA-504 | SY4S-51F1 | -- | ||
| SM2S-62 | 10A | PC board | -- | -- | -- | |||
| RU4 RU42 | Front Wiring Socket (*2) | SY4S-05B | 7A | Standard | SFA-202 | SFA-101 | -- | |
| SY4S-05C (*1) | 7A | Finger-safe | SFA-502 | -- | -- | |||
| SN4S-05D | 6A | Standard | -- | -- | SU9Z-S21R | |||
| SY4S-05DF (*1) | 6A | Finger-safe | SFA-301 | SY4S-51F1 | -- | |||
| SU4S-21L | 8A | Push-in (*3) | SFA-302 | -- | -- | |||
| Solder | SY4S-51 | 7A | Solder | -- | -- | -- | ||
| Rear Wiring Socket | SY4S-61 | 7A | PC board | SFA-504 | SY4S-51F1 | -- | ||
| SY4S-62 | 7A | PC board | -- | -- | -- |
Notes: *1) Finger-safe cannot be used with ring terminal. *2) Front wiring sockets can be mounted directly on DIN rail and mounting panels. *3) SU2S-21L and SU4S-21L are Push-in sockets; no tightening screws required. Stranded wire, solid wire, and ferrules can be attached using a screwdriver.
Hold-down Springs
| Style | Shape | Material | Part No. | Ordering No. | Package Quantity |
|---|---|---|---|---|---|
| Wire Spring | Stainless Steel | SY4S-51F1 | SY4S-51F1PN10 | 10 | |
| Leaf Spring | Stainless Steel | SFA-101 | SFA-101PN20 | 10 pairs | |
| SFA-202 | SFA-202PN20 | ||||
| SFA-301 | SFA-301PN20 | ||||
| SFA-302 | SFA-302PN20 | ||||
| SFA-502 | SFA-502PN20 | ||||
| SFA-503 | SFA-503PN20 | ||||
| SFA-504 | SFA-504PN10 | 10 |
Notes: • A relay requires a pair of leaf springs, except for SFA-504 (one spring per relay). • When using wire spring SY4S-51F1 or leaf spring SFA-504 with a latching lever relay, the lever cannot be opened or closed. • Leaf springs (except SFA-504) cannot be removed after installation on a socket.
Accessories for Sockets
| Name | Shape | Specifications | Part No. | Ordering No. | Package Quantity | Remarks |
|---|---|---|---|---|---|---|
| DIN Rail | Aluminum Weight: Approx. 200g Length: 1m Width: 35 mm | BAA1000 | BAA1000PN10 | 10 | ||
| End Clip | Zinc-plated steel Weight: Approx. 15g | BNL5 | BNL5PN10 | 10 | Used on a DIN rail to fasten relay sockets | |
| BNL6 | BNL6PN10 | 10 | ||||
| DIN Rail Spacer | Plastic (black) Thickness: 5 mm | SA-406B | SA-406B | 1 | Used for adjusting spacing between sockets mounted on a DIN rail | |
| End Spacer | Plastic (black) | SA-203B | SA-203B | 1 | Used for mounting DIN rail mount sockets directly on a panel surface | |
| SA-204B | SA-204B | 1 | ||||
| Jumper (for 2-pole socket) | Brass (Nickel-plated) with polyprene sheath | SM9Z-JF2 | SM9Z-JF2PN10 | 10 | Used for interconnecting relay coil terminals on SM2S-05DF sockets; can be cut to required length. No. of sockets: SM9Z-JF2: 2, SM9Z-JF5: 5, SM9Z-JF8: 8 | |
| SM9Z-JF5 | SM9Z-JF5PN10 | |||||
| SM9Z-JF8 | SM9Z-JF8PN10 | |||||
| Jumper (for 4-pole socket) | Brass (Nickel-plated) with polyprene sheath | SY9Z-JF2 | SY9Z-JF2PN10 | 10 | Used for interconnecting relay coil terminals on SY4S-05DF sockets; can be cut to required length. No. of sockets: SY9Z-JF2: 2, SY9Z-JF5: 5, SY9Z-JF8: 8 | |
| SY9Z-JF5 | SY9Z-JF5PN10 | |||||
| SY9Z-JF8 | SY9Z-JF8PN10 |
Safety Precautions
- Turn off the power to the relay before starting installation, removal, wiring, maintenance, and inspection. Failure to do so may cause electrical shock or fire hazard.
- Observe specifications and rated values to prevent electrical shock or fire hazard.
- Use wires of the proper size and tighten terminal screws to the specified torque.
- Before operating the latching lever, turn off the power to the relay. Return the lever to its original position after checking the circuit.
- Do not use the latching lever as a switch.
- The latching lever durability is a minimum of 100 operations.
- When using DC loads on 4PDT relays, apply appropriate voltage polarity to neighboring poles to prevent short circuits.
- DC relays with diodes have polarity in their coil terminals.
- Surge absorbing elements (RC for AC, diode for DC) protect against counter electromotive force. For excessive external surges, additional protection may be needed.
Instructions
Driving Circuit for Relays
- Apply rated voltage to the relay coil for correct operation.
- For DC coils, a stable DC voltage is recommended. If using a power supply with ripple voltage, suppress the ripple factor to within 5%. For rectification circuits, connect a smoothing capacitor to improve operating characteristics. The ripple factor is calculated as: `Ripple factor (%) = ((Emax - Emin) / Emean) * 100%`.
- When operating relays in synchronism with AC loads, relay life may be reduced. Consider reliability requirements or operate the relay irrespective of the AC power phase, ideally near the zero-voltage crossing point.
- Leakage Current: When driving other elements simultaneously, leakage current (Io) flowing through the relay coil when off can cause release failure or affect vibration/shock resistance. Ensure proper circuit design to prevent this.
- Surge Suppression for Transistor Circuits: High-voltage pulses generated when the coil is turned off can damage transistors. Connect a diode to suppress counter electromotive force. For faster coil release, a Zener diode with a voltage slightly higher than the power voltage can be connected between the collector and emitter of the transistor.
Protection for Relay Contacts
- Do not exceed contact ratings. Inrush current can cause contact welding. Use a current limiting resistor if necessary.
- Contact Protection Circuits: For inductive loads, arcing can form carbides on contacts, increasing resistance. Surge absorbing circuits (RC, Diode, Varistor) are recommended to improve reliability, contact life, and noise suppression. Note that release time may increase slightly.
- Circuits to Avoid: Certain protection circuits, like those using a capacitor discharged through contacts upon closing, can increase the risk of contact welding.
- Switching DC inductive loads is more challenging than resistive loads. Appropriate arc suppressors improve switching characteristics.
Other Precautions
- Do not drop or shock the relay. Do not remove the relay cover during normal operation.
- Use relays in environments free from condensation, dust, sulfur dioxide (SO2), and hydrogen sulfide (H2S).
- Ensure coil voltage does not exceed the applicable range.
- Connecting outputs to fast-responding electronic circuits requires consideration for contact bounce, which can cause incorrect operation. Use integral circuits or suppress bounce pulses.
- UL- and CSA-approved ratings may differ from IDEC's product ratings.
- Avoid using relays near strong magnetic fields, as they can affect operation.
- DC diode types have polarity.
- Surge absorbing elements are provided for coil protection. For excessive external surges, additional protection might be needed.
Ordering Terms and Conditions
By purchasing IDEC products, you agree to these terms and conditions.
Notes on Catalogs:
- Rated values are acquired under specific conditions and do not guarantee performance in combined conditions or all environments.
- Reference data is for reference only.
- Specifications, appearance, and accessories are subject to change without notice.
- Catalog content is subject to change without notice.
Note on Applications:
- Confirm applicable laws, regulations, and standards when combining IDEC products with other products.
- Verify compatibility with your systems under actual conditions. IDEC is not liable for compatibility issues.
- Usage examples are for reference only; confirm performance and safety before use.
- Implement safety designs with sufficient allowance, redundancy, and malfunction prevention.
- Perform periodic maintenance to prevent issues like abnormal heat or fires due to performance deterioration.
- IDEC products are general-purpose and not intended for applications requiring extremely high safety, reliability, or unusual operating environments. Consult an IDEC sales representative for such applications.
Inspections:
Implement inspections promptly and maintain products carefully.
Warranty:
- Warranty period is one (1) year from purchase/delivery, unless otherwise specified.
- IDEC will repair or replace products failing due to IDEC's fault within the warranty period. Failures due to misuse, modification, external causes, or improper maintenance are excluded.
Limitation of Liability:
IDEC's liability is limited to product repair or replacement. Special, indirect, incidental, or passive damages are excluded.
Service Scope:
Services like installation guidance, maintenance, and technical training may incur separate fees. Consult an IDEC sales representative for regional transactions and usage.
