Hydraulic injection molding machines are among the highest energy-consuming pieces of equipment in any manufacturing facility. A large share of that energy does not go into production. It gets lost inside the machine as heat, noise, and pressure bleed off. For many owners, this means paying for electricity that delivers no output.
Shenzhen VEIKONG Electric Co., Ltd. offers the VFD550I electro-hydraulic servo inverter as a direct solution to this problem. It is built specifically for hydraulic systems and designed to match motor output to actual machine demand at every stage of the molding cycle. Factories using it report power savings between 20% and 60%.
This blog covers why the energy waste happens, how the VFD550I addresses it, and what improvements you can expect after installation.
The Real Problem with Traditional Hydraulic Injection Machines
Here is the core issue. A traditional hydraulic injection molding machine uses a constant-speed oil pump. The motor drives the pump at full speed from the moment it starts until the moment it stops. It does not matter whether the machine is doing heavy injection work or just sitting in the cooling phase. The motor keeps going at the same pace.
The molding process has multiple stages. Mold locking, injection, pressure holding, material melting, cooling, mold opening, and part ejection. Each of these stages needs a different amount of pressure and flow from the hydraulic system. Some stages are demanding. Others barely need anything at all.
With a fixed-speed pump, the system cannot adjust. When demand is low, all that extra hydraulic pressure has to go somewhere. It gets pushed through damper valves, heats the oil, and generates noise. None of that is useful work. It is just a waste.
The traditional fixed oil-supply systems waste at least 50% of the energy consumed. Think about what that means for your electricity bill every single month.
Side Effects of Constant Full-Speed Operation
The side effects of this constant full-speed operation go beyond energy waste:
- The hydraulic oil overheats regularly, shortening the life of the fluid and the system.
- Valves and seals wear out faster because they are always under pressure.
- The machine runs loudly, making the working environment unpleasant.
- Maintenance costs creep up over time as parts need replacing more often.
How the Injection Molding Process Works
Each production cycle on an injection molding machine goes through a set sequence. First, the mold locks shut. Then the material gets injected under high pressure and held there briefly. After that, the machine melts and feeds fresh material for the next shot. The part then cools inside the mold. Finally, the mold opens, and the finished part gets pushed out.
Every step in that sequence calls for something different from the hydraulic system. Injection needs high pressure and high flow. Cooling needs almost nothing. The mold locking stage sits somewhere in between. The whole cycle keeps shifting back and forth between high demand and low demand.
A motor running at a fixed speed cannot respond to any of that. It just runs flat out regardless. That mismatch is what creates the waste.
What the VFD550I Actually Does
The VFD550I reads the pressure and flow signals coming from the injection molding machine’s control system. Based on those signals, it adjusts the motor speed up or down in real time to give the hydraulic system exactly what it needs for each stage of the cycle.
High pressure needed? The motor speeds up to match. Cooling phase with almost no demand? The motor slows right down. Machine sitting idle? The motor stops completely. No wasted energy, no unnecessary heat, no excess noise.
This is the fundamental difference between a fixed-speed system and a servo inverter drive. The motor only works as hard as the job requires at that specific moment.
The VFD550I works with both standard asynchronous motors and permanent magnet synchronous motors. It supports encoderless vector control, which means you do not necessarily need to add encoder hardware to get good results. This makes it practical to retrofit onto existing machines without tearing everything apart.
Features Worth Knowing About
The VFD550I was designed specifically for hydraulic applications. It is not a general-purpose drive that someone has tried to repurpose. The engineering inside it reflects the real demands of injection molding work.
- The built-in pressure control algorithm is fast and stable. Pressure overshoot stays within 1% and steady-state fluctuation holds within 0.5 Bar. For molding work where consistency matters, that level of precision makes a difference in part quality.
- Overall power savings land between 20% and 60% depending on your machine and production setup. Many factories recover the cost of installation within a year just from electricity savings.
- Automatic zero drift correction keeps the system accurate over time without your operators needing to fiddle with settings constantly.
- Weak magnetic control performance is improved by 10% compared to standard drives, which benefits factories running permanent magnet synchronous motors at higher speeds.
- The drive supports incremental encoders and rotary transformers, so it can work with the encoder types already installed on most machines in the field.
- Both closed-loop and open-loop vector control are supported. If you have encoder feedback available, use it for tighter control. If not, open-loop vector control still delivers strong results.
- Temperature protection is built in with standard PTC support. PT100, PT1000, and KTY84 sensors are available as options for more detailed monitoring.
Technical Specifications
- Voltage: 380V to 480V three-phase
- Power range:7 kW to 710 kW
- Motor support: Asynchronous motors and permanent magnet synchronous motors
- Control modes: V/F, sensorless vector control, vector control
- Standard communication: RS-485
- Optional communication: PROFINET, CAN bus
- Protection rating: IP20
- Brake unit: Built-in up to 90 kW, external for 110 kW and above
What Changes After Installation
Factories that install the VFD550I on their hydraulic injection molding machines notice a few things fairly quickly. Here are some changes that occur after installation:
1. The Power Consumption Drops
For some machines and production schedules, the savings are modest. For others, especially machines with long cooling cycles or lots of idle time, the savings are significant. Either way, the electricity meter slows down.
2. The Machines Get Quieter
When the motor is only running as fast as it needs to, the hydraulic system is not constantly working against itself. The noise level in the workshop drops noticeably.
3. The Hydraulic Oil Stays Cooler
Lower oil temperature means the fluid lasts longer before it needs changing. It also means seals and valves are not under constant heat stress, so they hold up better over time.
4. Part-Quality Improves
Precise pressure control through each stage of the molding cycle means the machine follows its programmed parameters more closely. Fewer short shots, fewer flash defects, more consistent cycle times.
5. Maintenance Intervals Stretch Out
When nothing is running harder than it needs to, things simply do not break as often. The molds last longer. The pump lasts longer. The whole hydraulic system holds up better.
Shenzhen VEIKONG Electric Co., Ltd: Widely Trusted for VFD550I Servo Inverter
Shenzhen VEIKONG Electric Co., Ltd. has been in the variable frequency drive business since 2004. That is over 20 years of focused work in researching, manufacturing, and supplying AC drive solutions to industrial customers around the world.
Who They Are
VEIKONG is a professional AC drive enterprise with its own R&D team and management staff who have worked in this field for decades. The company covers everything from the initial research and product design through to manufacturing and global supply.
Their drives are built to international standards and are positioned as direct replacements for well-known brands from Europe, America, and Japan.
What They Offer
VEIKONG produces a broad range of drive products to cover different application needs:
- General-purpose AC drives such as VFD500, VFD530, and VFD550I series.
- Economic AC drives for applications where cost is the main consideration.
- Premium vector drive systems for applications demanding superior performance.
- Solar-powered pumps for farming and water supply off-grid.
- Soft starters for soft starting of motors without excessive electrical strain.
- VFDs that are specialized and tailored for certain industry uses.
Industries Served
Some of the industry-specific solutions that have been developed by VEIKONG are listed below:
- Hydraulic press machinery
- Fans & pumps of the oil industries
- Applications of air compressors
- Crane and hoisting machinery
- Water supply & pump machinery
- Solar water pumps
- Disk washers and moulding machinery for plastics
Their Global Presence
VEIKONG supplies products to clients across more than 200 countries and regions. The company uses SPWM, sensorless vector control, and torque control technologies in its drives, meeting advanced international standards and delivering strong technical performance wherever they operate.
Want to Know More?
If your hydraulic injection molding machines are running up a high electricity bill and you want to understand what the VFD550I could do for your operation, the VEIKONG team can help. They have technical staff available to look at your specific application and work out the right configuration for your machines.
You can download the VFD550I product brochure and user manual from the VEIKONG website at veikong-electric.com.
For general questions, write to info@veikong-electric.com. For technical support, contact Service@veikong-electric.com. To speak with someone directly, call +86-0755-89587650 or reach the team on WhatsApp at +86 15989436541.
Shenzhen VEIKONG Electric Co., Ltd. is located at 4F, Building 5, Dongluyang Industrial Park, No. 4, Tengfeng 4th Road, Fuyong Phoenix Third Industrial Zone, Baoan District, Shenzhen, China.