Inovance MD500 Series Inverter Hardware Manual Guide: System Configuration, Installation, Technical Specifications and Maintenance

Overview of the MD500 Hardware Platform

The Inovance MD500 series is a general-purpose high-performance current vector inverter designed for controlling and regulating the speed and torque of three-phase AC asynchronous motors. It serves a broad spectrum of industrial applications including textile machinery, paper processing, wire drawing, machine tools, packaging equipment, food processing lines, fans, pumps, and various automated production systems. This hardware manual guide covers the physical aspects of the MD500 platform: system configuration and model naming, technical specifications across voltage classes and power ranges, mechanical and electrical installation requirements, EMC compliance, accessory selection, and maintenance procedures.

System Configuration and Model Naming

Model Number Decoding

The MD500 model number follows a structured naming convention that encodes the voltage class, power rating, load type, and feature options. The general format is:

MD500 – [Voltage] [Power] [Load Type] [Options] [-T]

• Voltage class: T = Three-phase 380-480V; 2S = Single-phase 200-240V; 2T = Three-phase 200-240V; 7T = Three-phase 690V
• Power rating: Numerical value in kW (e.g., 0.4, 7.5, 55, 450)
• Load type: G = General-purpose (constant torque, heavy duty); P = Pump/fan (variable torque, light duty)
• Options: B = Built-in brake unit; -T = Built-in DC reactor; -L = Long dimensions variant for larger frames
• Narrow body designation: H suffix indicates a narrow-body enclosure for space-constrained installations

For example, model MD500T55GB-T represents a three-phase 380V, 55kW, general-purpose inverter with built-in brake unit and built-in DC reactor. Model MD500-2S0.4G represents a single-phase 220V, 0.4kW, general-purpose inverter without brake unit.

Frame Sizes T1 through T13

The MD500 series encompasses 13 frame sizes (T1 through T13) that cover the full power range from 0.4kW to 630kW. The frame size determines the physical dimensions, terminal specifications, cooling requirements, and installation method:

Frame	Power Range (380V G-type)	Cooling Method	Installation
T1	0.4 – 3.0 kW	Natural convection / small fan	Wall mount / rail mount
T2	3.7 – 5.5 kW	Forced air cooling	Wall mount
T3	7.5 – 11 kW	Forced air cooling	Wall mount
T4	15 kW	Forced air cooling	Wall mount
T5	18.5 – 22 kW	Forced air cooling	Wall mount
T6	30 – 37 kW	Forced air cooling	Wall mount
T7	45 – 55 kW	Forced air cooling	Wall mount / floor mount
T8	75 – 90 kW	Forced air cooling	Floor mount
T9	110 – 132 kW	Forced air cooling	Floor mount
T10	160 – 200 kW	Forced air cooling	Floor mount with rail
T11	220 – 280 kW	Forced air cooling	Floor mount with rail
T12	315 – 450 kW	Forced air cooling	Floor mount with rail
T13	500 – 630 kW	Forced air cooling	Floor mount with auxiliary cabinet

Product Component Architecture

The MD500 hardware consists of several key components that vary by frame size:

• Control board: Contains the DSP processor, parameter storage (EEPROM), control terminal blocks, communication interface (RS485), and PG card slot. Identical across all frame sizes.
• Driver board (power board): Interfaces between the control board and the power module. Provides gate drive signals, current sensing, voltage sensing, and protection circuits. Varies by frame size and voltage class.
• Power module (IGBT): The main switching elements that convert DC to AC PWM output. Small frames use integrated IPM modules; larger frames use discrete IGBT packages.
• Rectifier module: Converts AC input to DC bus voltage. Small frames use integrated bridge rectifiers; larger frames use discrete rectifier diodes.
• DC bus capacitors: Filter the DC bus voltage and provide energy storage for transient loads. Capacitor capacity scales with frame size and power rating.
• Cooling fan(s): Provide forced air flow across the heatsink. The number and size of fans increase with frame size (T1 has one small fan; T12-T13 may have multiple large fans).
• Soft-start contactor: In models above approximately 15kW, a bypass contactor shorts out the pre-charge resistor after DC bus capacitor charging is complete, reducing power loss and heat generation.
• DC reactor: In models with the -T suffix, the DC reactor is built into the drive between the rectifier and the DC bus capacitors, reducing input harmonic current and improving power factor.

Technical Specifications

Voltage Classes and Power Ranges

The MD500 series covers four voltage classes, each with its own range of power ratings and model configurations:

Voltage Class	Input Voltage	Power Range	Frame Sizes	Output Voltage
Single-phase 200-240V	200-240V AC, 50/60Hz	0.4 – 2.2 kW	T2	3-phase 200-240V
Three-phase 200-240V	200-240V AC, 50/60Hz	0.4 – 200 kW	T1 – T12	3-phase 200-240V
Three-phase 380-480V	380-480V AC, 50/60Hz	0.4 – 630 kW	T1 – T13	3-phase 380-480V
Three-phase 690V	575-690V AC, 50/60Hz	55 – 560 kW	T7 – T13	3-phase 690V

Key Electrical Specifications (380V Class)

Specification	G-type (Heavy Duty)	P-type (Pump/Fan)
Rated input voltage	380-480V AC, 3-phase	380-480V AC, 3-phase
Input frequency	50/60 Hz, ±5%	50/60 Hz, ±5%
Output voltage	0-100% of input voltage	0-100% of input voltage
Output frequency	0-590 Hz	0-590 Hz
Overload capacity	150% for 60s, 180% for 10s	120% for 60s
Control method	SVC, FVC, V/F	SVC, V/F
Speed accuracy (SVC)	±0.5% of rated speed	±0.5% of rated speed
Speed accuracy (FVC)	±0.01% of rated speed	N/A
Starting torque	150% at 0.5 Hz (SVC), 180% at 0 Hz (FVC)	150% at 0.5 Hz
Carrier frequency	0.5-16 kHz (derated above rated)	0.5-16 kHz
Input power factor	≥0.95 (with DC reactor)	≥0.95 (with DC reactor)
Efficiency	≥97% (rated load)	≥97% (rated load)

Environmental Specifications

• Operating ambient temperature: -10°C to +50°C (no derating); +50°C to +55°C with 2% derating per °C above 50°C
• Storage temperature: -20°C to +60°C
• Humidity: 5% to 95% RH, non-condensing
• Altitude: Up to 1000m without derating; 1000-4000m with 3% derating per 100m above 1000m
• Vibration: 5.9 m/s² (0.6g), 10-55 Hz; 2 m/s² for T8 and above
• Protection class: IP20 (standard); up to IP54 with optional enclosure modifications
• Pollution degree: PD2 (designed for industrial environments)

Mechanical and Electrical Installation

Mechanical Installation

The MD500 can be installed in three configurations depending on frame size and application requirements:

• Wall mounting: Applicable to T1 through T9 frames. The drive is mounted vertically on a flat, vibration-free surface using the mounting holes on the rear of the enclosure. For T1-T2 frames, a standard 35mm DIN rail mounting option is also available.
• Embedded (flush) mounting: Using optional embedded mounting brackets (MD500-AZJ-A1T1 through A1T9), the drive can be mounted flush with a control panel surface, with only the front cover visible. This provides a cleaner appearance and protects the drive from dust in the panel interior. Embedded mounting is available for T1-T9 frames only.
• Floor mounting with installation rail: For T10-T13 frames, the drive is mounted on a specialized installation rail (MD500-AZJ-A3T10) that allows the drive to be pushed into a cabinet on rails, simplifying the installation of heavy drives. T13 frames may require an auxiliary distribution cabinet for peripheral components.

Critical installation clearances must be maintained for proper cooling:

• Vertical clearance: Minimum 100mm above and below the drive for T1-T6; minimum 300mm above and below for T7-T13
• Horizontal clearance: Minimum 50mm on each side for T1-T6; minimum 100mm for T7-T13
• Multiple drive installation: When installing multiple drives vertically, maintain at least the vertical clearance between each drive, or use a deflector plate between drives to prevent upper drive exhaust from entering the lower drive intake

The drive must be installed on a non-flammable, flat surface capable of supporting its weight. For T8 and above (75kW+), the weight exceeds 35kg and the mounting surface must be structurally reinforced. The installation location should be free from direct sunlight, corrosive gases, excessive dust, and excessive vibration.

Electrical Installation

Main Circuit Terminal Wiring

The main circuit terminals on the MD500 follow the standard Inovance convention with R, S, T (input), U, V, W (motor output), P(+) and N(-) (DC bus), BR (brake resistor), and PE (protective earth). Key wiring requirements include:

• Use a molded-case circuit breaker (MCCB) or residual current device (RCD) between the power supply and the drive, sized to the drive’s rated input current
• Use a magnetic contactor for power on/off control — but never use the contactor to start/stop the drive during normal operation, as frequent contactor operation reduces capacitor and contactor life
• Never connect input power to the output terminals (U, V, W) — this will destroy the drive
• Never install power factor correction capacitors or surge suppressors on the output side
• For models without built-in DC reactor, install an AC input reactor to reduce harmonic distortion and improve power factor
• Install a brake resistor between P(+) and BR when regenerative energy from deceleration or overhauling loads needs to be dissipated
• Use symmetrical shielded cables for both input and output power connections to minimize electromagnetic radiation
• Tighten all main circuit terminals to the specified torque — undertightening causes overheating and fire risk, overtightening damages terminals

Recommended tightening torques for main circuit terminals range from 1.2 N·m (M4 screws, T1-T2 frames) to 85.0 N·m (M16 screws, T13 frame). The specific torque for each frame size is specified in the cable selection tables.

Cable Selection

The MD500 hardware manual provides detailed cable selection tables for each voltage class, specifying the recommended cable cross-section, cable lug model, screw size, and tightening torque for each drive model. The tables are organized by frame size (T1-T13) and cover both IEC (mm²) and UL (AWG) cable standards.

Key principles for cable selection:

• Input cable cross-section is based on the rated input current and must account for ambient temperature and routing method
• Output cable cross-section can typically be one size smaller than input cable, as the output current may be lower than input current due to power factor differences
• Grounding cable cross-section must meet local electrical code requirements (typically same size as input cable for drives up to 37kW, half size for larger drives)
• Control cables must use shielded twisted pair cables, with analog and digital signals in separate cables
• For motor cable lengths exceeding 100m, an output reactor or filter must be installed to reduce capacitive leakage current and dV/dt stress on motor insulation

The cable lug models recommended in the manual include TNR series (for T1-T4 frames, M4-M5 screws), GTNR series (for T5-T9 frames, M6-M8 screws), and BC series (for T10-T13 frames, M12-M16 screws). Using the correct lug ensures proper electrical contact and thermal performance at the terminal connection.

Control Terminal Wiring

The MD500 control terminal block provides the following connections:

Category	Terminals	Specifications
Analog power	+10V, GND	+10V reference for potentiometer (1-10kΩ), max 10mA
Digital power	+24V, COM	+24V for DI/DO, max 200mA
Analog inputs	AI1, AI2, AI3 (with IO card)	0-10V or 0/4-20mA, selectable via jumper S1/S2/S3
Digital inputs	DI1-DI5 (DI6-DI10 with IO card)	24V level, DI5 supports high-speed pulse up to 100kHz
Digital outputs	DO1, DO2	Optocoupler isolated, open-collector, 0-24V, max 50mA
Relay outputs	TA/TB/TC (RELAY1), RA/RB/RC (RELAY2 with IO card)	Dry contact, AC 250V/3A, DC 30V/1A
Analog outputs	AO1, AO2	0-10V or 0/4-20mA, selectable via jumper
Pulse output	FMP, GND	0-50kHz, open-collector output
Communication	RS+, RS-	RS485, isolated, supports Modbus-RTU

EMC Compliance and Wiring

The MD500 series complies with IEC/EN 61800-3:2004 (adjustable speed electrical power drive systems, EMC requirements and specific test methods) and IEC/EN 61800-5-1:2003 (safety requirements). To achieve EMC compliance, the following installation practices are required:

EMC Wiring Requirements

• Grounding: The drive PE terminal must be connected to the system ground using a conductor of adequate cross-section. The grounding impedance must be low enough to ensure fault current can flow. Use a flat braided grounding strap for high-frequency grounding.
• Cable shielding: Both input and output power cables must use symmetrical shielded cables (three conductors + ground, symmetrically arranged). The shield must be grounded at both ends with 360° shield clamps. Control cables must use individually shielded twisted pairs.
• Cable routing: Power cables and control cables must be routed in separate conduits or trays with a minimum separation of 100mm. If crossing is unavoidable, cables must cross at 90° angles.
• EMC input filter: For installations in residential or commercial environments (C2 category), an EMC input filter must be installed between the power supply and the drive. The filter must be mounted on the same metal panel as the drive, with the filter housing in direct metal-to-metal contact with the panel.
• Output reactor or filter: For motor cable lengths exceeding 50m (unshielded) or 100m (shielded), an output reactor or dV/dt filter must be installed to limit capacitive leakage current and protect motor insulation.
• Ferrite cores: For applications with sensitive equipment nearby, ferrite cores can be installed on the motor cable, wrapped with 2-3 turns, to reduce high-frequency radiation in the 30-1000 MHz range.

Leakage Current Considerations

Variable frequency drives generate leakage current due to the high dV/dt of PWM output voltage and the parasitic capacitance between motor cables and ground. This leakage current can cause RCDs to trip inadvertently. Mitigation measures include:

• Use RCDs specifically designed for variable frequency drive applications (type B RCDs with time delay)
• Reduce the carrier frequency (F0-15 parameter) to decrease leakage current, accepting increased motor noise
• Shorten motor cable length or use shielded cable with lower capacitance per meter
• Install output reactors to reduce dV/dt and capacitive coupling

Selection of Accessories

Input AC Reactors

Input AC reactors are recommended for all installations to improve power factor, reduce input harmonic current, and protect the drive rectifier from voltage transients. They are essential when:

• The power supply capacity exceeds 500kVA (or the drive rated current is less than 1% of the supply short-circuit current)
• The power supply has power factor correction capacitors switched on the same bus
• The drive is installed within 10km of a large-capacity thyristor converter
• The supply voltage imbalance exceeds 3%

The reactor impedance is typically 3-5% of the drive rated impedance. The MD500 manual provides detailed reactor selection tables (model RWK series from Schaffner) with inductance values and power loss for each drive model. For models with built-in DC reactor (-T suffix), the external AC input reactor may be omitted in many standard installations, though it is still recommended for applications with poor power quality.

Output Reactors

Output reactors protect motor insulation from voltage reflections caused by long cable runs and reduce motor audible noise, motor temperature rise, and leakage current. They are required when:

• Motor cable length exceeds 50m (unshielded cable) or 100m (shielded cable)
• The motor does not have reinforced insulation (non-inverter-duty motors)
• Multiple motors are connected to one drive with long combined cable runs

The manual provides output reactor selection tables with models (RWK series), inductance values (ranging from 1.47mH for 0.4kW drives down to 0.005mH for 630kW drives), and power dissipation values for each drive model.

Brake Resistors and Brake Units

For applications with frequent deceleration or overhauling loads, brake resistors dissipate regenerative energy that would otherwise raise the DC bus voltage above safe limits. The brake resistor selection depends on:

• The regenerative power and duty cycle of the application
• The brake unit action voltage (F9-08, default 760V for 380V drives)
• The braking torque requirement (typically 100-150% of rated torque)

For drives with built-in brake units (B suffix models), only an external brake resistor is required. For drives without built-in brake units, an external brake unit (such as Inovance BUE series) must be installed between P(+) and N(-), with the brake resistor connected to the brake unit. The manual provides brake resistor selection tables with recommended resistance values, power ratings, and duty cycle capabilities for each drive model.

EMC Filters

EMC input filters reduce conducted electromagnetic interference from the drive back into the power supply. The MD500 manual specifies EMC filter models compatible with each drive model. Key installation requirements for EMC filters include:

• The filter must be mounted on the same metal panel as the drive
• The filter housing must have direct metal-to-metal contact with the panel (no paint or insulation between filter and panel)
• The filter PE terminal and drive PE terminal must be connected to the same ground point
• The cable between filter output and drive input should be as short as possible (maximum 30cm)
• The filter must be rated for the drive’s rated current and voltage

PG (Encoder) Cards

The MD500 supports a comprehensive range of PG cards for encoder feedback in FVC (closed-loop vector control) mode:

PG Card Model	Encoder Type	Interface	Key Features
MD38PG1	Differential ABZ (5V)	DB9	500kHz max, standard differential encoder
MD38PG3	Differential UVW + ABZ (5V)	DB15	For PMSM with UVW commutation signals
MD38PG4	Resolver	DB9	12-bit resolution, 10kHz excitation, DC resistance >17Ω required
MD38PG4D	Resolver with frequency division	DB9	Same as PG4 plus differential frequency division output
MD38PG5	Open-collector (15V)	Terminal block	100kHz max, for open-collector encoders
MD38PG5D	Open-collector with division	Terminal block	Same as PG5 plus frequency division (DIP switch 4-62)
MD38PG6	Differential (5V)	Terminal block	500kHz max, terminal block interface
MD38PG6D	Differential with division	Terminal block	Same as PG6 plus frequency division (DIP switch 4-62)
MD38PGMD	Universal (diff/OC/push-pull)	Terminal block	5V/15V selectable power, division 0-63, multi-function
MD38PGMD2-ZL	Universal with CPLD division	Terminal block	Enhanced version of PGMD with CPLD-based division

IO Expansion Cards

The MD38IO3 IO expansion card adds 3 digital inputs (DI6-DI8), 1 digital output (DO3), 1 relay output, 1 analog input (AI3), and 1 analog output (AO2) to the standard drive I/O. The expansion card is automatically recognized by the drive upon installation, and the additional terminals appear in the F4/F5 parameter groups.

Communication Expansion Cards

Communication expansion cards enable the MD500 to integrate with various industrial networks:

• MD500-PN1/PN2: PROFINET communication card, supporting cyclic data exchange and acyclic parameter access
• MD-SI-DP1: Profibus-DP communication card for integration with Siemens and other Profibus-based systems
• EtherCAT card: For high-speed EtherCAT-based automation systems
• CANopen card: For CANopen-based distributed control

Operation Panels and Accessories

• MD32NKE1: LED external operation panel for remote mounting via RJ45 cable
• MDKE9: LCD external operation panel with Chinese/English display, USB parameter upload/download, and parameter copy capability
• MDCAB: 3-meter extension cable (standard 8-core RJ45) for connecting external panels
• MDCAB-1.5: 1.5-meter extension cable variant
• MD500-AZJ-A2T1 through A2T9: Cable shield grounding brackets for 360° shield grounding
• MD500-NEMA1-T1 through T6: Conduit box kits for UL Type 1 enclosure compliance

Maintenance and Inspection

Routine Maintenance Schedule

Period	Inspection Items	Actions
Daily	Ambient temperature, ventilation, abnormal sounds/odors, motor current, input voltage	Visual and auditory inspection; record readings
Quarterly	Screw tightness on main circuit and control terminals; cable insulation; dust accumulation; cooling fan operation	Re-tighten terminals; clean dust with compressed air; verify fan rotation
Annual	Main circuit insulation resistance; electrolytic capacitor condition; motor insulation; EMC filter continuity; brake resistor resistance	Megger test (500V DC, >5MΩ); visual capacitor inspection; record trending data
2-year	Full internal inspection by qualified technician; control board battery replacement (if applicable); firmware update if available	Schedule factory service if needed

Cooling Fan Maintenance

The cooling fans are critical components with a design life of approximately 5 years under rated conditions (40°C ambient, 80% load, 24h/day). Fan failure is the most common cause of module overheating faults (Err14). The MD500 manual provides fan replacement procedures for each frame size:

• T1-T3 frames: Single fan, replaced from the bottom of the drive after removing the bottom cover
• T4-T6 frames: Single or dual fans, accessible from the front after removing the front cover
• T7-T9 frames: One or two large fans, replaced from the side after removing the side cover
• T10-T13 frames: Multiple fans in a fan tray assembly, replaced as a unit

Fan failure can be detected proactively by monitoring the fan running time parameter and scheduling replacement before the 5-year design life is reached. Some fans also include a rotation detection signal that triggers an alarm when the fan stops.

Electrolytic Capacitor Maintenance

The DC bus electrolytic capacitors have a design life of approximately 5-8 years under rated conditions. Capacitor degradation is accelerated by high ambient temperature, high ripple current, and frequent voltage transients. Signs of capacitor degradation include:

• Bulging or leakage from the capacitor vent
• Increase in DC bus ripple voltage (observable via monitoring parameters)
• Reduced ride-through capability during power interruptions
• Increase in input current harmonics

Capacitor replacement should be performed by qualified service personnel, as the capacitors store charge even after power is disconnected. Always wait at least 5 minutes after power-off and verify that the DC bus voltage is below 36V before touching any internal components.

Main Circuit Insulation Test

The main circuit insulation test is a critical annual maintenance procedure. The test must be performed correctly to avoid damaging the drive:

1. Disconnect all power from the drive and wait at least 5 minutes for DC bus discharge
2. Disconnect the motor cables from the U, V, W terminals
3. Disconnect the brake resistor from the P(+) and BR terminals
4. Remove the VDR (varistor) screws to disconnect the varistors from the circuit — failure to do this will destroy the varistors
5. Short all main circuit terminals together (R, S, T, U, V, W, P+, N-, BR)
6. Apply 500V DC from a megger between the shorted terminals and the PE terminal
7. The insulation resistance must be ≥5MΩ
8. After testing, reinstall the VDR screws and reconnect all cables

The control circuit must never be tested with a megger. Control circuit integrity can be verified by visual inspection and functional testing only.

Long-Term Storage

If the drive is to be stored for more than 3 months without operation, the following procedures are recommended to maintain capacitor health:

• Store in a dry, dust-free environment at -20°C to +60°C
• Apply power to the drive for at least 2 hours every 6 months to reform the electrolytic capacitors (connect input power only; no motor connection required)
• If power application is not possible, store with the drive in its original packaging with desiccant packets
• Before returning to service after extended storage, perform a full inspection including megger test and capacitor visual inspection

Conclusion

The Inovance MD500 series hardware platform provides a robust and flexible foundation for general-purpose industrial drive applications across an exceptionally wide power range (0.4kW to 630kW) and four voltage classes. The 13 frame sizes ensure appropriate physical sizing for each application, while the comprehensive accessory ecosystem — including PG cards, IO expansion cards, communication cards, operation panels, installation brackets, reactors, filters, and brake resistors — enables configuration for virtually any industrial automation scenario.

The detailed cable selection tables, terminal torque specifications, and EMC installation guidelines provided in the hardware manual ensure that installers can achieve reliable electrical connections and electromagnetic compatibility. The structured maintenance schedule, covering daily inspections through annual megger testing and component life management, supports long-term reliability and minimizes unplanned downtime.

The MD500’s modular hardware design — with replaceable cooling fans, accessible capacitor banks, auto-detecting expansion cards, and standardized terminal layouts — simplifies both initial installation and ongoing maintenance. Combined with the comprehensive fault protection system and the three motor control modes (SVC, FVC, V/F) configurable through the same hardware platform, the MD500 delivers the performance, flexibility, and reliability demanded by modern industrial drive applications.