Allen-Bradley 825-P

The Allen-Bradley 825-P Modular Protection System is a flexible protective device to monitor 3-phase motor control systems and supervise the critical points of such systems. The Allen-Bradley 825-P has been designed to be a very cost-effective unit while still offering maximum motor efficiency. The Allen-Bradley 825-P demonstrates the compatibility of the 825-MCM420 converter, which supervises controls of the primary power circuit. It also allows for a Voltage input card which has a working voltage rating of 67 to 300-Volts Alternating Current at an impulse strength of 4 kilovolts at a frequency of 50/60 hertz (plus or minus 5 hertz). The 825-P’s control circuit has a control supply voltage of 110-240 Volts Alternating Current at a frequency of 50 to 60 hertz with a maximum power consumption rating of 15 volt-amperes.

The 825-P only has a single Normally Open (N.O.) relay contact with a voltage of 240 Volts Alternating Current while operating at 3 amperes of working current. The 825-P also provides an impulse strength of 4 kilovolts with a pickup duration of less than 10 milliseconds. This unit also offers an insulation voltage rating of 300 Volts Alternating Current. The system also features overload protection and optional voltage-based protection. The Allen-Bradley 825-P includes a built in keypad on its front panel for ease of use, along with an LED status indicator for immediate and quick user responses. The 825-P also uses the DeviceNet communication system to transmit data at a speed of 125, 250, or 500 Kilobyte per second at distances of 100, 200, or 500 meters. It is also protected in a National Electrical Manufacturers Association (NEMA) 4 IP65 Rated enclosure.

The menu of the 825-P is split into ten different sections, each with their own range of data and setting details. The 825-P comes with customizable identifier settings that users may set. The setting range for the protection relay is 16 characters and includes capital letters from a to z, numbers 0 through 9, periods, dashes, and spaces. Allen-Bradley suggests identifiers include the location, process, circuit, size, or equipment number of the protected motor. The 825-P prints the relay and terminal identifier strings at the top of responses to serial port commands to identify messages from individual relays. The 825-P can be mounted in a sheltered indoor environment, such as a building or an enclosed cabinet, which does not exceed the temperature and humidity ranges for the protection relay. The relay can also be mounted indoors or in an extended outdoor enclosure where the relay will be protected from direct sunlight exposure, precipitation, and full wind pressure, but where neither temperature nor humidity are controlled. This protection relay can also be flush mounted, give that the user cuts a rectangular hole with the correct dimensions. The device requires a power supply voltage of 110-210 VAC and 16 AWG size or heavier wire must be used to connect to the isolated power terminals. Operational power is internally fused by the power supply fuse.

The Allen-Bradley 825-P is equipped with a PTC Thermistor Input. This input is a Mark A control unit and has a maximum of six (6) sensors in a series. Additionally, the maximum cold resistance of the PTC Sensor Chain is 1500 ohms. The trip resistance of this input is 3400 ohms, plus or minus 150 ohms. The resistance for reset ranges from 1500 ohms to 1650 ohms. The short circuit trip resistance of this product is 25 ohms, plus or minus 10 ohms. The ambient temperature when operating the 825-P is negative twenty (-20) to positive sixty (+60) degrees Celsius, or negative four (-4) to positive one hundred and forty (+140) degrees Fahrenheit. When storing the Allen-Bradley 825-P, however, the ambient temperature should remain within a range of negative forty (-40) to positive eighty-five (+85) degrees Celsius, or negative forty (-40) to positive one hundred and eighty-five (+185) degrees Fahrenheit. The humidity range when operating the Allen-Bradley 825-P should be noncondensing and within a range of five percent (5%) to ninety-five percent (95%). The maximum altitude that this product should be operating at is two thousand (2000) meters. 

The Allen-Bradley 825-P has a relay front panel that allows for many features and interactions for an operator. The front panel is equipped with a liquid crystal display, or LCD. This display shows information, both real-time and historic, and also relay setting menus. Also equipped to the front panel is a keypad that houses six (6) keys. These keys include one (1) "escape" key and one (1) "enter" key, as well as four (4) navigation keys. These navigation keys are up, down, left, and right and are used to navigate through menus or data lists. There are two (2) LEDs on the panel, one (1) for "Enable" and another for "Trip." Additionally, the front panel is equipped with an EIA-232 serial port.