Cabin support frame anti overload weighing system, for lifts and goods lift freight elevators.
699Plus digital device for load weighing with inclination control
The 699Plus M device is a digital device for measuring, displaying, and controlling the load in lift cabins, with a visualization on a 4-digit high-brightness display. This version of the product has been developed in order to allow the load limiter to be connected to a bi-axial inclinometer of the ES270 series (measuring range ± 45 ° for each axis) so that the instrument can be used as a load limiter (2 relays, with freely adjustable thresholds) and as an inclination limiter (1 relay, with an intervention linked to the exceeding of a threshold that can be set for the X measuring axis or when the exceeding of the threshold of the Y measuring axis). The choice of this measurement system is for lifts installed on board cruise ships to prevent the use of the system in choppy sea conditions, where pitching and rolling over the limits set could make the operation of the lift unreliable.
The device, when connected to the inclinometer, makes the following possible, in addition to the typical measurement functions related to the load present in the cabin:
- Alternate loading and inclination display (X and Y axis, with 1st degree resolution)
- Resetting the inclination measurements to zero, on the inclinometer’s installation position
- the assignment of angle limits – for intervention of relay 3 – that are independent for X axis and Y axis
- verification and diagnostic indications for the connection between instrument and inclinometer
It is moreover possible to use this measuring system on vehicles as a load limiter that is able to assess the attitude of the vehicle by dynamically limiting the liftable/transportable load so as to avoid overturning the vehicle or prevent load displacements.
Relays in the unit can be connected – as the installer chooses – as Normally Open (NO) or Normally Closed (NC).
The 699Plus load weighing device is suitable for new lifts and for the modernization of old plant systems, being easy and fast to install, reliable over time and at a good price.
Automatic zeroing reset functions of the measurements, catenary compensation with relay blocks while the car is moving, and the possibility of using a calibration procedure (MANU) with sample weight or a sample weight-free calibration (AUTO) procedure are available, going to call up calibration profiles for S2Tech production sensors that are defined on a statistical basis with test campaigns carried out in our laboratories using the most commonly available rope samples
It is possible by means of the relays, to pilot warning lights and alarms for the indication of overloads in the cabin (default threshold value of 110% of the nominal load), as well as indicating the presence of load conditions close to the nominal system limit (default value 80% of nominal load) to the plant system controller. It is moreover possible to order the device with the optional analog voltage or current output (SINK type), which is proportional to the load present in the cabin – so as to control the starting torque of the winch and achieve an improvement in the comfort of the plant.
In this product configuration, the digital communication port is dedicated to the connection with the inclinometer (supplied already calibrated) and is therefore not available to connect the instrument to the plant system controller.
At the end of every calibration, the device verifies the quality of the calibration performed by the installer by reporting fault conditions related to electrical or procedural wiring errors (through error codes for a facilitated assistance) that might affect the quality of the measurement. All data is stored in EEprom memory, so it is not necessary to rely on backup batteries, to the benefit of the reliability and durability of the device. For added security there is also a relay test mode, which the installer can use when needed.
The displays of this series are designed and manufactured in Italy, with EMC testing carried out with third-party laboratories in order to validate the product against the effect of electrical disturbances that might be present in the lifts of modern design. Before delivery, each instrument is individually tested with a calibration with a reference load cell to verify all different measuring functions of the device.
It is possible to connect this series of strain gauge sensor displays that have been specifically designed by S2Tech to be installed on lifts or with load cells or pressure transducers for industrial applications where automatic control of the forces or loads being applied is required.
There are several different product configurations for connecting the sensor to the instrument through RJ11 connectors, through a screw terminal, or in order to permit the connection to up to 8 S2Tech production transducers by means of Minifit connectors. In order to the guarantee maximum reliability, the electrical connection systems have always been chosen that are fitted with retaining connectors, in order to avoid unintended disconnections, to the detriment of the effectiveness of the load control system.
The instrument can be supplied as a simple printed circuit for integration into the machine’s electrical control panel, or supplied with a robust metal housing that makes it possible to mount it in difficult conditions from a mechanical point of view.
There is a 4-button keyboard for programming the unit, LEDs for indications of the power supply and relay status and two opto-isolated digital inputs for remote activation of the measuring instrument. The analog output and digital output may be installed, as options, at the same time and are fully configurable by the User.
The 699Plus series instruments find their application as load limiters on lifts or other industrial lifting systems, for theatrical applications, on machines, weighing systems (fixed or on board the vehicle) and industrial applications.