Model 4485

Regular price $452.00

Model 4485 Anti-Tiedown Switch Monitor with PLC Interface

The 4485 Switch Monitor is designed to provide two-hand control for machines which are using a PLC to control its operation. Most PLCs should not be used for safety applications because they are not of “control reliable contruction” as defined by OSHA. Therefore, an anti-tiedown control, such as the 4485 control, is needed in order to meet OSHA’s “Control Reliability” standards. [Sec. 1910.217(b)(13)].


Anti-tiedown – The 4485 requires an operator to have both hands on start switches in order to start machine operation. This minimizes the possibility of the operator starting the machine while his hand is in the work area.

PLC Interface – The 4485 has a solid state output which interfaces with PLCs that have sinking or sourcing inputs.

Control Reliability – The 4485 is designed to meet the OSHA classification of “control reliability” as defined in section 1910.217(13).

Redundant Output Contacts – The 4485 uses double “positive guided” output relays. Each relay is checked for proper status prior to beginning a machine cycle.

Hand Switch Inputs – The 4485 is designed to interface with dry contact single pole hand switches and electronic hand sensing devices.

Low Voltage Detector – If the supply line voltage to the 4485 drops below 90 VAC (115v operation), the 4485 will not allow the load to be energized.

Easy Wiring – The 4485 is wired using a detachable terminal strip for easy installation and removal. The control also includes a wire for connection to the PLC.


If both start switches are closed within a time of .5 seconds, the PLC port and the load output will be energized. The PLC port is wired to the input of the PLC, and signals the PLC to start the machine cycle. The load output can be wired to supply power to the outputs of the PLC, so that the PLC outputs will only be energized when both start switches are activated. The output contacts will remain closed until one or both start switches are released.

Maintained Output – An optional Hold switch can be wired into the 4485 to provide a maintained output. When the Hold switch is closed, the load will stay energized even after the start switches are released. The Hold switch must not close until the machine passes the pinch-point, and it should remain closed for the rest of the machine cycle.

If the optional Reset switch is opened at any point during the machine cycle, the outputs will de-energize and the control will reset. Both start switches must be open and the Reset switch must be closed before another machine cycle can be started. Isolated output contacts of the PLC can be used to control the optional Hold and Reset features. This will allow the PLC to control timing and other operations that may determine when the machine cycle should end.


Physical Dimensions

120mm x 100mm x 50mm (4.7″ x 3.7″ x 2.0″)


0.6 kg (1.25 lbs)

Power Requirements

115 VAC, 50/60 Hz @ .1A 230 VAC, 50/60 Hz @ .05A

Power Line Monitor

Resets if supply drops below 90V RMS (115V application), 180V RMS (230V application) for more than 15ms.

Output Load Rating

8 Amps (Switching)6 Amps (Continuous)

Output Life

10 million mechanical operations (minimum)

Hand Switch Delay

.05 to .15 seconds (factory set at .075 seconds)

Switches must be activated within:

0 to .7 seconds (factory set at .5 seconds)

Delay on Power-up

5 seconds (approximate)

Temperature Range

Up to 60°C (140°F)


Made in U.S.A.


Nolatron 4480 Brochure

Nolatron 4485 Application Notes