CU4
Réference: CU4
Description
The CU4 is an off-delay timing unit which can be operated standalone or as an extension of a host relay. The timed outputs are used in applications where power must be maintained for a fixed duration after an input signal is received. For example, driving a power to lock TLS2-GD2 to maintain a guard door in the locked position for a fixed duration after a stop button is pressed. Another example would be maintaining the connection of a drive to a motor until the braking function is achieved, and then dropping out a contactor to remove power to the motor.
The inputs can be connected in either a single channel or dual channel configuration. The inputs must remain open during the complete timing cycle. Closing the contacts before the timing cycle completes causes the timer to be reset to zero.
The CU4 has a redundant structure with two independent safe timer circuits. The outputs include two normally open safety delayed outputs as well as one normally closed auxiliary output. The safety outputs have independent and redundant internal contacts to support the safety function. When used as an extension of a host relay, the normally closed contacts should be used in the feedback loop of the host relay. If used in standalone application, the normally closed contacts can be used to signal an auxiliary device or PLC.
A typical operation starts with power applied to A1/A2 and the input circuits open.
1. Close the B11/B12 and B21/B22 circuits.
a. The safety outputs (17/18 & 27/28) close immediately.
2. Open the B11/B12 or B21/B22 circuits.
a. The timing process starts.
b. The safety outputs (17/18 & 27/28) open after the time expires.
3. Go to Step 1.
Features
- Category 3 per EN 954-1
- Stop category 1
- Timed off-delay 0.15…30 s
- Two safety contacts
- One auxiliary contact
LED Indicators
| Green | Power |
| Green | CH1 t1 Active |
| Green | CH2 t2 Active |
Specifications
| Safety Ratings | ||
| Standards | EN 954-1, ISO 13849-1, IEC/EN 60204-1, IEC 60947-5-1, ANSI B11.19, AS4024.1 | |
| Safety Classification | Cat. 3 per EN 954-1 (ISO 13849-1), SIL CL2 per EN IEC 62061, PLe per ISO 13849-1 | |
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Functional Safety Data ⋆ Note: For up-to-date information, visit http://www.ab.com/safety/ |
PFHD: < 2.16 x 10-9 MTTFd: > 345 years Suitable for performance levels Ple (according to ISO 13849-1:2006) and for use in SIL3 systems (according to IEC 62061) depending on the architecture and application characteristics |
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| Certifications | CE Marked for all applicable directives, cULus, c-Tick, and BG | |
| Power Supply | ||
| Input Power Entry | 24V AC/DC, 50/60 Hz; 0.85…1.1 x rated voltage | |
| Power Consumption | 2.5 W | |
| Inputs | ||
| Safety Inputs | 1 N.C. or 2 N.C. | |
| Input Simultaneity | Infinite | |
| Reset | Automatic | |
| Response Time | 30 ms | |
| Outputs | ||
| Safety Contacts | 2 N.O. | |
| Auxiliary Contacts | 1 N.C. | |
| Rated Impulse withstand Voltage | 2500V | |
| Switching Current @ Voltage, Min. | 10 mA/10V | |
| Fuses, Output | External 6 A slow blow or 10 A fast acting | |
| Electrical Life (Operations) |
220V AC/4 A/880VA cosf = 0.35…0.1 M 220V AC/1.7 A/375VA cosf = 0.6…0.5 M 30V DC/2 A/60 W = 1 M 10V DC/0.01 A/0.1 W = 2 M |
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| Mechanical Life | 2,000,000 operations | |
| Utilization Category | ||
| AC-15 | 5 A @ 250V AC | 5 A @ 125V AC |
| DC-13 | 3 A/24V DC | |
| UL: | B300, 5 A/250V AC, 24V DC | |
| Environmental and Physical Characteristics | ||
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Enclosure Type Rating/ Terminal Protection |
IP40, DIN 0470/ IP20 |
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| Operating Temperature [C (F)] | -5…+55 ° (23…131 °) | |
| Vibration | 10…55 Hz, 0.35 mm | |
| Shock | 10 g, 16 ms, 100 shocks | |
| Mounting | 35 mm DIN Rail | |
| Weight [g (lb)] | 165 (0.36) | |
| Conductor Size, Max. | 0.2…4 mm2 (24…12 AWG) | |
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⋆ Usable for ISO 13849-1:2006 and IEC 62061. Data is based on the following assumptions: - Mission time/Proof test interval of 20 years - Functional test at least once within six-month period |
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Product Selection
| Inputs | Safety Outputs | Auxiliary Outputs | Time Range | Reset Type | Power Supply | Cat. No. |
| 1 N.C. or 2 N.C. | 2 N.O. | 1 N.C. | 0.15…3s | Automatic |
24V AC/DC, 50/60 Hz 0.85…1.1 x rated voltage |
440R-S23173 |
| 0.5…10s | 440R-S23174 | |||||
| 1.5…30s | 440R-S23175 | |||||
Approximate Dimensions
Dimensions are shown in mm (in.). Dimensions are not intended to be used for installation purposes.
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Block Diagram
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Typical Wiring Diagrams
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| Dual Channel Wiring to CU4 Inputs |
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| Single Channel Wiring to CU4 Inputs |