Consider the following basic objectives when defining an intelligent motor relay:
- Increase reliability, improve safety, and reduce the operating costs of motor systems.
- Minimize time to commission and maintain.
- Standardize real time motor and operational data for integration into control system for process optimization.
- Access and integrate all available operational and diagnostic data for immediate and future use.
Realizing these objectives is based on the core capabilities of the intelligent motor relay to include direct measurement of motor voltage, current and temperature, control the operation of a motor starter, easily configured fault and warning parameters and standardized communications options for integration to plant control systems.
A typical intelligent motor relay consists of a measurement module, control module, I/O module, user interface and communications module. Options in the form factor of these components allows for the installation in existing motor control centers and stand alone motor control enclosures as well as new replacement motor control systems.
Consider the following criteria when evaluating an intelligent motor relay:
- Pre-fault warning. A user definable threshold separate of the actual fault threshold, to provide an earlier indication of fault. User selectable with programmable delay.
- Fault (trip) function. User defined fault threshold with a programmable delay at parameter level. Programmable override or disable feature, independently selectable for application specific concerns.
- Local fault capture. Upon a fault condition, the device will capture a group of diagnostic parameters (time stamped) and store them in non-volatile memory (see detail below).
- Start Cycle and Transition Timing. Device shall recognize motor stop, motor start and motor transition modes of operation to align start and run protection/operation profiles.
- Overload Protection. Is a function of NEMA trip class selection and designed thermal capacity of the motor. Device shall allow for programmable selection of standard trip classes and thermal modeling of motor condition protected in non-volatile memory.
- Setpoint security. Programmable security to limit those who can change setpoints, fully protecting setpoint standards.
- Thermistor/RTD input. Means of monitoring winding and bearing temperature via sensing device, providing for fault and display functionality.
- Local display. Accessory options should include an appropriate HMI display that can be installed locally to the device (panel or MCC bucket door), assisting technicians with troubleshooting.
- Common communication protocol options; EtherNet I/P, Profinet, Modbus TCP, etc.
- Device health. Onboard diagnostics to alert and fault if device components including power supply, microprocessor, memory, analog-to digital converters, or other related functions fail.
- Commissioning. Pre-defined device data mapping, as well as sample configuration packages suitable for reuse. This includes tags aliasing and device register pre-mapping. A device interface, accessible through a standard web browser, will be provided to ease commissioning and create reusable templates.
- Field servicing. May include but is not limited to replacing a single component within a device, re-addressing communications, or replacing the entire device itself. Such servicing must be attainable through traditional maintenance personnel, enabled through the following options:
- A device installed; non-volatile memory module is provided for parameter back up. If a device fails, a new unit can be commissioned in the field by transferring the memory module.
- A factory default IP addressing scheme should be utilized to allow technicians to set IP addressing without any interface or programming requirement. One such available option allows the last octet of the IP address to be set with device DIP switches.
Intelligent motor relays can be an integral part in your journey to smart manufacturing and really take you plant to the next level in industry 4.0.