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CU4
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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 |