Timing Control Unit

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CU1

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Approximate Dimensions Block Diagram Typical Wiring Diagrams Application Details
Click to enlarge - 440R-E23159-195_Product

Description

The CU1 is an on-delay timing unit designed to energize and thus unlock guard locking devices after a preset time delay expires. It can be used with power to unlock devices, like the Allen-Bradley Guardmaster Atlas, Spartan, 440G-MT, or TLS-GD2, on machines which have a run down cycle or do not stop immediately. It may also be incorporated into other parts of the safety related controls system, should a predictable, on-delay be required.

A removable cover allows access to the AC power switch, the replaceable fuse, and the DIP switches & potentiometer which control the timing. Power to the CU1 can be either 24V AC/DC (+/- terminals) or 110/230V AC (A1/A2 terminals). If 110V AC or 230V AC power is used, an internal switch must be set to the appropriate position.

The X1/X2 terminals are designed to monitor the performance of the contactors which isolate the power to the moving parts of the machinery. The timing can not begin until the X1/X2 loop is closed. The X1/X2 loop must remain closed during the whole timing cycle. Opening the X1/ X2 loop during the timing cycle causes the time to be reset to zero. If monitoring is not needed, the X1/X2 loop can be linked.

A typical operation starts with the safety outputs (13/14 and 23/24) open and the X1/X2 loop closed.

1. Apply power to A1/A2 or +/-.
  a. The Power LED turns ON and the Output LED turns red.
  b. After the time delay expires, the Output LED turns green and the safety outputs (13/14 and 23/24) close.
2. Remove power to A1/A2 or +/-.
  a. Immediately, the safety contacts (13/14 and 23/24) open, the Power LED turns off and the Output LED turns Off.
3. Go to step 1.

The status of the CU1 can be signaled to the Remote Indicator Unit via terminals R1/R2/R3, or to a PLC or other indicator by using the N.C. auxiliary contacts (31/32).

Features