Setup: Trystar M850-MP1 Multi Power Meter Instruction Manual

Overview

The M850-MP1 Multi Power Meter is a panel-mounted AC measuring instrument for monitoring voltage, current, frequency, power, power factor, energy, and demand. It is designed for electrical panels, load banks, distribution equipment, and other installations where operators need local readings from single-phase or three-phase systems.

The meter uses front-panel buttons to organize measurements into four display groups: current, voltage and frequency, power, and energy. Optional plug-in modules add RS485 Modbus communications or relay-based energy pulse output.

Specifications

• Model: M850-MP1 Multi Power Meter
• Voltage input range: 28 to 330 V AC line-to-neutral or 48 to 570 V AC line-to-line
• Current input: 0.5 to 6 A through current transformers
• Voltage and current input burden: Less than 0.5 VA
• Frequency range: 45 to 65 Hz
• Auxiliary supply: 100 to 440 V AC or 100 to 420 V DC
• Auxiliary supply burden: Less than 10 VA
• Voltage accuracy: 0.5% plus or minus 2 digits
• Current accuracy: 0.5% plus or minus 2 digits
• Power accuracy: 1.0% plus or minus 2 digits for W, VAr, and VA
• Power-factor accuracy: 1% of range
• Frequency accuracy: 0.1 Hz
• Energy accuracy: IEC 1036 Class 1
• Overload capability: 800 V line-to-line indefinitely and 10 times rated current for 1 second
• Display: Three lines of four-digit, 7-segment characters
• Character height: 14.2 mm
• Display update time: 1 second
• Optional ports and outputs: Plug-in RS485 Modbus module and plug-in W.h or VAr.h relay module
• Enclosure: DIN-style case measuring 96 x 96 x 60 mm
• Panel cutout: 92.8 x 92.8 mm
• Mounting: Four retaining clips
• Operating temperature: 0 to 60°C
• Storage temperature: -40 to 85°C
• Relative humidity: 0 to 95%, non-condensing
• Shock rating: 30G in two planes

Detailed Description

The M850-MP1 measures AC system quantities through voltage connections and current transformers. The programmed system type tells the meter how to interpret the connected conductors and whether the installation is balanced or unbalanced.

The meter supports 1-phase, 2-wire; 1-phase, 3-wire; 3-phase, 3-wire; and 3-phase, 4-wire arrangements. Balanced versions of the 3-phase, 3-wire and 3-phase, 4-wire configurations are also available in the setup menu.

Current measurements include individual line currents, neutral current where applicable, current demand, and maximum current demand. Voltage screens provide phase-to-phase and phase voltage readings, while the frequency screen reports the system frequency.

Power screens provide total watts, reactive power in VAr, apparent power in VA, average power factor, demand, and maximum demand. Energy screens provide accumulated import watt-hours and import reactive volt-ampere-hours.

When the optional RS485 module is installed, the instrument can communicate with monitoring equipment, programmable controllers, computers, and data loggers through the Modbus protocol. The optional relay module can produce energy pulses representing W.h or VAr.h.

Safety

• Installation and wiring should be performed by qualified personnel familiar with electrical measurement equipment and the connected power system.
• Disconnect and isolate all relevant power sources before working on wiring or removing the meter from a panel.
• The secondary connection of every current transformer must be connected to earth as specified for the installation.
• Do not leave a current-transformer secondary disconnected while the primary conductor is energized.
• Use voltage and current connections that remain within the meter’s specified input ranges.
• Unused voltage terminals are internally connected; verify the wiring arrangement before applying power.
• Confirm that the programmed voltage ratios, current settings, and system type match the installed transformers and electrical system.
• Apply the auxiliary supply only within the stated AC or DC auxiliary-voltage limits.
• After configuration, compare displayed voltage and current values with known system values before relying on the readings.

Setup and Operation

Display Controls

Press the appropriate front-panel button to select a measurement group:

• I: Current readings
• V/Hz: Voltage and frequency readings
• P: Power readings
• E: Energy readings

Press the same button repeatedly to move through the measurements in that group. The meter stores the selected display state for each button.

Adjusting Display Brightness

Hold the two center buttons simultaneously to adjust the LED display brightness. Use this function to improve readability for the panel’s lighting conditions.

Entering the Settings Menu

1. Press and hold the I and E buttons together for approximately 5 seconds.
2. When the display shows the settings menu, use E to scroll through menu items.
3. Press I to open or select the displayed item.
4. Use E to change a list selection or increment a digit.
5. Use I to accept the current selection and move to the next item.
6. Choose CONF to apply changes or CNCL to discard changes within a submenu.
7. Select END to leave the settings menu and return to measurement screens.

If no button is pressed for approximately 6 minutes, the meter exits the settings menu automatically. A confirmation screen may require I for Yes or E for No.

Supply Configuration

The SUPP menu contains the electrical-system settings used to scale and interpret readings.

• System current: Sets the current-transformer primary value.
• Primary voltage: Sets the voltage-transformer primary value.
• Secondary voltage: Sets the voltage applied to the meter input.
• System type: Selects the connected phase and wire arrangement.

Available system selections include 1P2 for 1-phase, 2-wire; 1P3 for 1-phase, 3-wire; 3P3 for 3-phase, 3-wire; 3P4 for 3-phase, 4-wire; 3P3B for balanced 3-phase, 3-wire; and 3P4B for balanced 3-phase, 4-wire.

Programming the System Type

1. Hold I and E together for approximately 5 seconds to enter setup.
2. Use E to reach TYPE in the supply submenu.
3. Press I to open the system-type selection.
4. Press E until the required configuration appears.
5. Press I to accept the configuration.
6. Scroll to CONF and press I to confirm the change.
7. Scroll to END and press I to return to normal measurement mode.
8. Check the displayed voltage and current values, including the decimal position.

Programming Voltage-Transformer Values

1. Enter the settings menu by holding I and E for approximately 5 seconds.
2. Open the SUPP submenu and select UPRI.
3. Use I to move through the digits of the primary-voltage value.
4. Use E to change the selected digit.
5. Set the decimal position when the display presents the decimal-point option.
6. Select the required exponent or descriptor, such as no descriptor, kilo, or mega.
7. Return to the supply submenu and select USEC.
8. Enter the secondary-voltage value using the same digit, decimal, and descriptor process.
9. Confirm the changes, exit through END, and verify the resulting voltage display.

Programming Current-Transformer Values

1. Enter setup by holding I and E together for approximately 5 seconds.
2. Open the supply submenu and select the system-current setting.
3. Use I to choose the digit to edit.
4. Use E to change the digit.
5. Set the decimal position and select the appropriate kilo, mega, or no-descriptor option.
6. Confirm the setting, leave the menu through END, and compare the displayed current with the expected system value.

Demand Measurements

The meter calculates demand using a sliding integration window for current, power, and apparent power measurements. The demand interval can be set from 3 to 60 minutes.

The DEMAND submenu includes a reset function. Resetting demand clears the current demand values and maximum demand records. Select the required demand time, confirm the setting, and verify the displayed demand after the next measurement interval has completed.

Energy Accumulators

The meter maintains separate import-energy accumulators for active energy and reactive energy. The ENERGY menu provides pulse-adjustment and reset functions.

Changing an energy divisor and confirming the change resets all energy readings. The energy reset command also clears all accumulated energy values, so record existing readings before using either function.

Relay Configuration

With the optional relay module installed, the relay can be configured for W.h or VAr.h pulse output. If two relays are installed, the secondary relay is automatically assigned the alternative energy type.

The relay pulse length can be selected from 0 to 200 milliseconds. Pulses per hour are entered through the meter’s digit, decimal-point, and exponent-entry method.

RS485 Modbus Configuration

The optional RS485 module provides Modbus communication. The COMMS submenu contains the communication parameters.

• Address: Sets the meter’s network address.
• Baud rate: Selectable values include 4800, 9600, 19200, 38400, or 57600 baud.
• Stop bits: Selects the supported stop-bit setting.
• Parity: Selects no parity, odd parity, or even parity.
• Endian: Selects Big Endian or Little Endian byte order for floating-point transmission.
• Lock: Helps prevent repeated network searching when communication errors are present.

The Modbus register map includes voltage, current, total kW, total kVA, total kVAr, average power factor, import energy, frequency, demand, maximum demand, and neutral-current values. The register listings use 3X and 4X address ranges.

Pass Code and Stored Settings

The CODE submenu allows a pass code to be edited and enabled to help prevent unauthorized changes to settings.

The EEPROM submenu stores configuration values in non-volatile memory. Save settings after completing configuration changes. The meter also saves settings during power-down or brownout conditions.

Troubleshooting

• Readings do not match the electrical system: Verify the selected system type, current-transformer primary value, voltage-transformer primary and secondary values, and decimal placement.
• Current readings appear incorrect: Confirm that each current transformer is connected to the correct phase and that the transformer secondary is properly connected and earthed.
• Voltage readings are incorrect: Check the voltage wiring, transformer ratio settings, unused terminals, and selected phase configuration.
• Demand values appear unexpected: Check the demand-window setting and allow a complete measurement interval after changing or resetting demand.
• Energy values changed unexpectedly: Confirm whether an energy divisor was changed or an energy reset was performed, since either operation can clear accumulated readings.
• RS485 communication fails: Confirm the meter address, baud rate, stop bits, parity, byte order, and lock setting match the host device.
• The meter leaves setup mode: Press a button before the approximately 6-minute inactivity timeout, then re-enter the menu if required.
• Display is difficult to read: Adjust LED brightness by holding the two center buttons.
• Displayed values have the wrong scale: Review the programmed decimal position and kilo, mega, or no-descriptor selection.

Pros & Cons

Pros

• Supports multiple single-phase and three-phase wiring configurations.
• Measures voltage, current, frequency, power, power factor, energy, and demand in one panel instrument.
• Offers configurable transformer ratios and display scaling.
• Provides optional Modbus communications and energy pulse relay output.
• Includes adjustable demand intervals, energy management, pass-code protection, and non-volatile settings storage.
• Uses a compact 96 x 96 mm panel format with a one-second display update.

Cons

• Correct transformer and system-type programming is required for accurate readings.
• Advanced communication, relay, and energy functions require the appropriate optional module.
• Changing energy divisors or resetting energy readings can clear accumulated data.
• Electrical installation requires careful attention to current-transformer safety and wiring configuration.