Making the Connections
The Floorpocket lift requires a Stagehand Pro AC and a Safety Interlock Box for operation. The Stagehand Pro AC has several key safety features not found in other Stagehand controllers that are critical for safe operation.
- Closed Loop vector mode for full-torque at zero-speed control
- Overspeed detection
- Safety Relay
- Ultimate Limit inputs
- Dual brake control
Connect the Pro Motor Cable manufactured by Creative Conners, Inc to carry power for the motor and brake from the Stagehand Pro AC to your Floorpocket Junction Box. We use a Harting IRC latching hood style connector for the Pro Motor Cable to ensure that your machine stays connected during operation.
You may be thinking, “wait, don’t we have all the safety we need already?”. Unfortunately a stage lift requires many safety features to keep everyone safe. These additional systems include bumper switches, safety mats and auxiliary limits, which are incorporated through the Safety Interlock Box.
The Safety Interlock Box sits between the Stagehand Pro AC and the Floorpocket, reading signals from the safety sensors and interrupting motion if any safety sensor is activated.
- 1.Three indicator lights to show the status of the Safety Interlock
- 2.Signal input from the Stagehand Pro AC
- 3.Signal output to the Floorpocket
- 4.Aux Limit connections, two each:
- 1.Ultimate, Forward, Reverse
- 5.Forward and Reverse sensors (one input and output for each direction)
- 6.Emergency Stop input and through
The Safety Interlock Pro requires a +24VDC Emergency Stop signal from a Showstopper 3 Base or Hub in order to allow motion. This +24VDC powers an internal safety relay, and you can daisy chain through to the Stagehand motion controller. The 5-pin XLR cable is not a DMX signal, but rather it was chosen as a convenient cable that is prevalent in many venues so you should always be able to find a spare cable when needed.
Below is the pin-out for the Emergency Stop input - polarity is important:
The Safety Interlock Pro adds additional support for 4 wire safety circuits (e.g. bumper switches, pressure mats). A 4 wire safety circuit, when used in conjunction with a safety relay, allows monitoring for the following four conditions:
- 1.Disconnected – The safety relay sends out test pulses through the sensor and expects the signal to return. If that signal does not return the safety relay will go into a faulted state and disallow any further motion.
- 2.Shorted – If a wire has been crushed by equipment or cut the safety relay will go into a faulted state.
- 3.Cross Circuit – If the signals get crossed and the test pulse comes back on the opposite channel the safety relay will go into a faulted state.
- 4.Good – If none of the above conditions occur the safety relay will not prohibit any movement.
There are 4 sets of safety sensors that are designed to be connected with the Floorpocket and the Safety Interlock Box.
- 1.Safety Pressure Mat (REV Safety Sensor)
- 2.Platform Safety Bumper Switches (REV Safety Sensor)
- 3.Trap Edge Safety Bumper Switches (FWD Safety Sensor)
- 4.Auxiliary Safety Sensors (optional)
The Interlock Aggregator Box is located inside the ModTruss frame of the Floorpocket. The Interlock Aggregator Box distributes the signal for the REV Safety Sensor of the Safety Interlock Box. Below are graphics that show how you should connect into the Interlock Aggregator Box and how the Interlock Aggregator Box is wired:
To prevent a Crush Hazard when the lift is lowering, we include a Safety Mat to stop the machine from running if there is pressure applied to the Safety Mat.
Install the Safety Mat by placing the Safety Mat under the platform and plugging both 3-pin XLR connectors into the Interlock Aggregator Box located inside the ModTruss Bottom Frame.
To prevent a Severing Hazard while the lift is lowering, we include Safety Bumpers already attached to the platform.
Simply verify that all 4 Safety Bumper Switches attached to the platform are connected together and wired to the Interlock Aggregator Box located inside the ModTruss Bottom Frame.
To prevent a Crushing Hazard while the lift is rising, we included Safety Bumper Switches for you to install around the opening of your stage.
To install your Trap Edge Safety Bumper Switches, slide the rubber bumper out of the aluminum mounting bracket. Use the holes in the mounting bracket to fasten the mounting bracket to the bottom side of the stage. Attach the mounting brackets around the perimeter of your stage opening, using the fasteners that attach best to your building structure. Then slide the rubber bumper back into the mounting bracket. Lastly, connect the 3-pin XLR connectors together in series and connect into the FWD Safety Sensor Connectors of your Safety Interlock Box.
The Auxiliary Safety Sensor is an additional available way to integrate a REV Safety Sensor. You may wonder why you would need an additional REV Safety Sensor. In some situations, you may need a larger platform than the stock 3ft x 3ft platform. If you do need a larger platform, please consult us here at Creative Conners, Inc. to make sure the new platform fits within the engineered specifications. With a larger platform, you will need to add an additional set of Safety Bumper Switches to the larger platform to prevent a Severing Hazard while the lift is lowering. If you are not using the Auxiliary Safety Sensor, make sure the included Interlock Jumper Cable is inserted into the Interlock Aggregator Box.
Two sets of encoder signals (one for speed monitoring and one for positioning) and three sets of limit switch signals (forward, reverse, and ultimate) are combined in one cable with a bulkhead connector (ILME CDDF-24). Encoders are powered at 5vdc for broadest compatibility.
All limit switch signals require Normally Closed (N.C.) switches. The Stagehand Pro AC sources 12vdc on a pin of each limit circuit and expects to see that 12vdc signal returned on the other pin when the limit is not activated. If the limit is either activated or disconnected, or a wiring fault occurs, the 12vdc return signal is interrupted and the Stagehand Pro AC will enter a limit fault condition and disallow motion.
The limit switch inputs are used to protect against the motor traveling too far in either direction and causing damage or injury. When running in a cue, this is one of the safety features that guards against overtravel due to encoder failure. When jogging manually, this keeps you from accidentally traveling too far. Limit switches use NEMA ML1 connectors.
The signal cable for the Floorpocket must be run through the Safety Interlock Box from the Stagehand Pro AC to operate. This means that you will need two signal cables. One to connect the Stagehand Pro AC to the Safety Interlock Box and a second to connect from the Safety Interlock Box to the Floorpocket.
On the Floorpocket we include a redundant set of end-of-travel limits. Like many of our machines, the Floorpocket come with FWD, REV, FWD ULT, and REV ULT Limits pre-installed on the machine. Below shows the location of each limit. Each limit needs to be plugged into the Limit J-Box.
Auxiliary Limits – These limits are wired in series with their corresponding standard limits. Thus, if a Forward Auxiliary limit is activated, the Stagehand Pro AC will read the limit as a Forward Limit. Similarly, if a Reverse Auxiliary limit is activated the Stagehand Pro AC will read the limit as a Reverse Limit. Auxiliary limits use NEMA ML1 connectors.
The Auxiliary Limits were originally conceived to be used with a Floorpocket and trapdoor (sunroof) application. This way, if you placed a Normally Open limit switch that is connected to the FWD Aux Limit input of the Stagehand Pro AC in the open position of your trapdoor (sunroof), this would prevent the lift from moving forward (or up) until the trapdoor (sunroof) is open. Similarly, you can do this with the REV Aux Limit to prevent the trap door from closing while the lift is in its raised position by placing a Normally Open limit switch where the limit is struck when the lift reaches its lowest position and is clear of the trapdoor (sunroof). If you are not using a trapdoor (sunroof) with your Floorpocket, you do not need Auxiliary Limits for your system. If you are not using a trapdoor (sunroof) with your Floorpocket, simply insert the included auxiliary limit jumpers to clear the limits. The graphic below shows how the limits could be placed for this system.
The graphic below shows the logic of how the interlock system controls the ability for motion to take place.