Variable speed
controller for pumps
VASCO – VAriable Speed COntroller is a purpose-built family of variable frequency drives, designed to control and protect pumping systems based on changing pump speed

VASCO – VAriable Speed COntroller
is a purpose-built family
of variable frequency drives,
designed to control and protect
pumping systems based
on changing pump speed
It can be installed directly on the motor or
directly to the wall with a supplied installation kit
The device can be installed
directly on the motor or
directly to the wall with
a supplied installation kit
Thanks to Nastec NOW App
it is possible to communicate with all
Nastec SMART Bluetooth® devices
VASCO – VAriable Speed COntroller is a purpose-built family of variable frequency drives, designed to control and protect pumping systems based on changing pump speed.
From water supply for domestic, irrigation, commercial and industrial applications, to heating and air conditioning, from filtering to pressure washing, the range perfectly fits any new or existing application ensuring:
Device units are extremely compact and, connected to any pump on the market, will manage the operation of the pump to maintain a constant desired physical dimension (such as pressure, flow, temperature or other). The pumping system runs only at the speed necessary to meet the user’s requirements, ensuring energy savings and extending the life of the system. It also provides motor protection and monitoring, such as:
The compact body is constructed entirely of aluminium, making device extremely solid, lightweight and easily cooled, adding to the unit’s versatility.
The IP55 degree of protection makes it possible to install it virtually anywhere, including humid and dusty environments. The illuminated liquid crystal display ensures it is easy to operate, and a buzzer provides an immediate indication of alarm.
VASCO – VAriable Speed COntroller is a purpose-built family of variable frequency drives, designed to control and protect pumping systems based on changing pump speed.
From water supply for domestic, irrigation, commercial and industrial applications, to heating and air conditioning, from filtering to pressure washing, the range perfectly fits any new or existing application ensuring:
Device units are extremely compact and, connected to any pump on the market, will manage the operation of the pump to maintain a constant desired physical dimension (such as pressure, flow, temperature or other). The pumping system runs only at the speed necessary to meet the user’s requirements, ensuring energy savings and extending the life of the system. It also provides motor protection and monitoring, such as:
The compact body is constructed entirely of aluminium, making device extremely solid, lightweight and easily cooled, adding to the unit’s versatility.
The IP55 degree of protection makes it possible to install it virtually anywhere, including humid and dusty environments. The illuminated liquid crystal display ensures it is easy to operate, and a buzzer provides an immediate indication of alarm.
When first powering the device, a quick initial wizard is required for complete configuration of the drive. Additional parameters can be configured later by entering three different setting levels:
The device can be installed directly on the motor with a supplied installation kit.
It is cooled by the motor cooling fan. Motor kit consists of 4 special clamps (or flange adapter) to secure the device to the motor fan cover (or motor feet).
The device can be installed directly to the wall with a supplied installation kit.
It is cooled by an external cooling fan attached to the inverter radiator. A special metal bracket is supplied for device to be mounted on the wall.
When first powering the device, a quick initial wizard is required for complete configuration of the drive. Additional parameters can be configured later by entering three different setting levels:
The device can be installed directly on the motor with a supplied installation kit.
It is cooled by the motor cooling fan. Motor kit consists of 4 special clamps (or flange adapter) to secure the device to the motor fan cover (or motor feet).
The device can be installed directly to the wall with a supplied installation kit.
It is cooled by an external cooling fan attached to the inverter radiator. A special metal bracket is supplied for device to be mounted on the wall.
Software implemented in each drive of VASCO – VAriable Speed COntroller range is the result of a long-time experience in solving customer requests and constantly following new drive applications.
Minimum motor frequency.
This parameter prevents motor operation below a certain frequency, thus avoiding damage to the thrust bearing of the submersible motors.
Minimum motor frequency ramp.
Motor can accelerate from 0 to the minimum motor frequency following a very fast ramp and then go through a slower ramp.
Intelligent stop of pump at no flow condition.
Below minimum control frequency, the device gradually reduces the pump speed while monitoring the pressure transducer signal. If this value is maintained close to the set pressure, the device will reduce furthermore the output frequency till stopping definitely the pump.
Maximum and minimum alarm pressure.
When the pressure rises above a certain settable pressure value, the device will stop the pump to prevent damage to the hydraulic components in the system. Similarly, if the pressure drops below a certain pressure an alarm is triggered and the pump is stopped.
Loss compensation proportional to the water flow.
If the pressure sensor is placed near the pump, with the increase in flow the pressure value at the furthest outlet is lower than the set pressure. It is possible to vary the set pressure in proportion to the frequency to compensate pressure loss in the pipes.
Dry running alarm via cosphi value.
If the pump runs dry, its cosphi value drops below a settable cosphi value, and the device stops the pump after 3 seconds. Device will try to make 5 attempts every 10, 20, 40, 80 and 160 minutes, after which it will trigger an alarm and stop the pump if the condition persists.
V/f programmable curve.
VASCO – VAriable Speed COntroller offers two different methods of torque control (voltage) versus pump speed (frequency):
For centrifugal pumps, energy savings can be obtained by selecting squared V/f control.
Settable carrier frequency between 2.5, 4, 6, 8, 10 kHz
If the device controls a submersible pump with long cables, it is possible to decrease the carrier frequency value to ensure longer motor life.
Software implemented in each drive of VASCO – VAriable Speed COntroller range is the result of a long-time experience in solving customer requests and constantly following new drive applications.
Minimum motor frequency.
This parameter prevents motor operation below a certain frequency, thus avoiding damage to the thrust bearing of the submersible motors.
Minimum motor frequency ramp.
Motor can accelerate from 0 to the minimum motor frequency following a very fast ramp and then go through a slower ramp.
Intelligent stop of pump at no flow condition.
Below minimum control frequency, the device gradually reduces the pump speed while monitoring the pressure transducer signal. If this value is maintained close to the set pressure, the device will reduce furthermore the output frequency till stopping definitely the pump.
Maximum and minimum alarm pressure.
When the pressure rises above a certain settable pressure value, the device will stop the pump to prevent damage to the hydraulic components in the system. Similarly, if the pressure drops below a certain pressure an alarm is triggered and the pump is stopped.
Loss compensation proportional to the water flow.
If the pressure sensor is placed near the pump, with the increase in flow the pressure value at the furthest outlet is lower than the set pressure. It is possible to vary the set pressure in proportion to the frequency to compensate pressure loss in the pipes.
Dry running alarm via cosphi value.
If the pump runs dry, its cosphi value drops below a settable cosphi value, and the device stops the pump after 3 seconds. Device will try to make 5 attempts every 10, 20, 40, 80 and 160 minutes, after which it will trigger an alarm and stop the pump if the condition persists.
V/f programmable curve.
VASCO – VAriable Speed COntroller offers two different methods of torque control (voltage) versus pump speed (frequency):
For centrifugal pumps, energy savings can be obtained by selecting squared V/f control.
Settable carrier frequency between 2.5, 4, 6, 8, 10 kHz
If the device controls a submersible pump with long cables, it is possible to decrease the carrier frequency value to ensure longer motor life.
With VASCO – VAriable Speed COntroller inverters is possible to realise booster sets with one or more pumps (up to 8) to be controlled at constant pressure.
The device can be mounted directly on the motor fan cover with a specific kit. The extreme strength of the connection allows its installation even on horizontal pumps.
Screen display can be easily rotated to optimise the parameter view.
Motor mounting – besides the compactness and the saving of additional control panels and wiring – guarantees very good cooling of the inverter and low electromagnetic emissions due to the reduced length of the motor cable.
IP55 protection allows installation in humid and dusty environments.
If device cannot be installed on the motor fan cover, it is possible to secure it to the wall with an optional kit composed by a cooling fan fed by itself and a metal wall bracket.
IP 55 protection does not require including the device drive in any additional control box so the device can be installed very near the pump.
COMBO mode control allows to switch the starting of pumps based on real working time and, in case of failure, the remaining pumps continue operation to always guarantee service.
Once the damaged unit is replaced, COMBO will preferably move the operation to the new pumps to equalise the running time.
A first way of splitting consists of installing one pump driven by device and 1 or 2 DOL pumps directly connected to the main power (Direct On Line); device switches on/off the 1 or 2 DOL pumps through contactors.
Device alter-nates the two DOL pumps to average pump wearing.
A second way of splitting (named COMBO) consists of using several pumps in parallel (up to 8) each one driven by a device unit.
In this way, efficiency and the reliability of the pump group is maximized.
Each device controls and protects its pump and the operation is shared among all the connected pumps to average pump wearing; in case of failure the remaining pumps will maintain the pumping operation.
Additionally it is possible to equip the system with pumps connected in COMBO mode plus 1 or 2 DOL pumps to satis-fy additional water demand.
In addition to constant pressure control, VASCO – VAriable Speed COntroller allows other control modes such as fixed frequency, constant flow, constant temperature.
Constant pressure.
It controls the pump speed to maintain constant pressure at a set point independent of the water demand in the system.
In a hydraulic system equipped with the device, the standard pressure tank is replaced by a smaller tank which functions to maintain the set pressure in the system when the pump is stopped.
Constant pressure 2 values.
By selecting the constant pressure 2 values control mode, in irrigation systems, only one pump can serve two zones with different pressure sets. It is possible to switch the two values by acting on a digit input contact.
Fixed frequency 2 values.
If it is not necessary to operate at constant pressure but is required to select 2 different pump speeds, by selecting fixed frequency 2 values control mode it is possible to switch the 2 values by acting on a digit input contact.
Constant temperature.
The control method at constant temperature is used to maintain the temperature of the pumped fluid to vary the thermal load. This control system is used in air conditioning or refrigeration and cooling towers. In this latter case, for example, the temperature measured by a sensor in the return water is kept constant.
External frequency.
In some application, it is chosen to change the frequency of the pump by using an external signal coming from a trimmer or a PLC. In this case, after selecting the External Frequency control mode, it is enough to connect an input signal 4-20 mA or 0-10V, proportional to the desired frequency, to the AN4 analogue contact.
Constant flow.
By selecting the constant flow control mode and using a flow transducer, it is possible to control the flow of the pumped liquid to vary the system condition.
This control mode is used, for example, in a system for filtering the pumped fluid in which the obstruction of the filter would lead to a progressive reduction of the flow rate if it is not compensated by an increasing of the pump speed.
Submersible pumps of various powers can be managed by VASCO – VAriable Speed COntroller.
Sometimes it is necessary to install a filter between pump and inverter to:
It is recommended to keep the motor cable separate from other cables, maintaining a certain distance. Nastec can provide filters and shielded cables for proper pump installation.
With VASCO – VAriable Speed COntroller inverters is possible to realise booster sets with one or more pumps (up to 8) to be controlled at constant pressure.
The device can be mounted directly on the motor fan cover with a specific kit. The extreme strength of the connection allows its installation even on horizontal pumps.
Screen display can be easily rotated to optimise the parameter view.
Motor mounting – besides the compactness and the saving of additional control panels and wiring – guarantees very good cooling of the inverter and low electromagnetic emissions due to the reduced length of the motor cable.
IP55 protection allows installation in humid and dusty environments.
If device cannot be installed on the motor fan cover, it is possible to secure it to the wall with an optional kit composed by a cooling fan fed by itself and a metal wall bracket.
IP 55 protection does not require including the device drive in any additional control box so the device can be installed very near the pump.
COMBO mode control allows to switch the starting of pumps based on real working time and, in case of failure, the remaining pumps continue operation to always guarantee service.
Once the damaged unit is replaced, COMBO will preferably move the operation to the new pumps to equalise the running time.
A first way of splitting consists of installing one pump driven by device and 1 or 2 DOL pumps directly connected to the main power (Direct On Line); device switches on/off the 1 or 2 DOL pumps through contactors.
Device alter-nates the two DOL pumps to average pump wearing.
A second way of splitting (named COMBO) consists of using several pumps in parallel (up to 8) each one driven by a device unit.
In this way, efficiency and the reliability of the pump group is maximized.
Each device controls and protects its pump and the operation is shared among all the connected pumps to average pump wearing; in case of failure the remaining pumps will maintain the pumping operation.
Additionally it is possible to equip the system with pumps connected in COMBO mode plus 1 or 2 DOL pumps to satis-fy additional water demand.
In addition to constant pressure control, VASCO – VAriable Speed COntroller allows other control modes such as fixed frequency, constant flow, constant temperature.
Constant pressure.
It controls the pump speed to maintain constant pressure at a set point independent of the water demand in the system.
In a hydraulic system equipped with the device, the standard pressure tank is replaced by a smaller tank which functions to maintain the set pressure in the system when the pump is stopped.
Constant pressure 2 values.
By selecting the constant pressure 2 values control mode, in irrigation systems, only one pump can serve two zones with different pressure sets. It is possible to switch the two values by acting on a digit input contact.
Fixed frequency 2 values.
If it is not necessary to operate at constant pressure but is required to select 2 different pump speeds, by selecting fixed frequency 2 values control mode it is possible to switch the 2 values by acting on a digit input contact.
Constant temperature.
The control method at constant temperature is used to maintain the temperature of the pumped fluid to vary the thermal load. This control system is used in air conditioning or refrigeration and cooling towers. In this latter case, for example, the temperature measured by a sensor in the return water is kept constant.
External frequency.
In some application, it is chosen to change the frequency of the pump by using an external signal coming from a trimmer or a PLC. In this case, after selecting the External Frequency control mode, it is enough to connect an input signal 4-20 mA or 0-10V, proportional to the desired frequency, to the AN4 analogue contact.
Constant flow.
By selecting the constant flow control mode and using a flow transducer, it is possible to control the flow of the pumped liquid to vary the system condition.
This control mode is used, for example, in a system for filtering the pumped fluid in which the obstruction of the filter would lead to a progressive reduction of the flow rate if it is not compensated by an increasing of the pump speed.
Submersible pumps of various powers can be managed by VASCO – VAriable Speed COntroller.
Sometimes it is necessary to install a filter between pump and inverter to:
It is recommended to keep the motor cable separate from other cables, maintaining a certain distance. Nastec can provide filters and shielded cables for proper pump installation.
VASCO – VAriable Speed COntroller, in addition to other control modes, performs the operation at constant differential pressure by using a differential pressure sensor or using 2 pressure sensors installed in the suction and delivery sides of the pump.
Difference value is calculated by itself from the two values read.
This solution enables significant cost savings as well as providing protection against cavitation (by setting a minimum alarm pressure on the suction side) and against overpressure (by setting a maximum pressure alarm on the delivery side).
Constant differential pressure control can be extended to operation in a group, i.e. twin pump application.
COMBO system ensures alternation of the pumps during operation to average the pumps’ wear and easily plan maintenance operations.
In systems characterized by high drops in pressure, the device performs the proportional differential pressure control to maximise energy saving.
VASCO – VAriable Speed COntroller, in addition to other control modes, performs the operation at constant differential pressure by using a differential pressure sensor or using 2 pressure sensors installed in the suction and delivery sides of the pump.
Difference value is calculated by itself from the two values read.
This solution enables significant cost savings as well as providing protection against cavitation (by setting a minimum alarm pressure on the suction side) and against overpressure (by setting a maximum pressure alarm on the delivery side).
Constant differential pressure control can be extended to operation in a group, i.e. twin pump application.
COMBO system ensures alternation of the pumps during operation to average the pumps’ wear and easily plan maintenance operations.
In systems characterized by high drops in pressure, the device performs the proportional differential pressure control to maximise energy saving.
Thanks to Nastec NOW App it’s possible to communicate with all Nastec devices Bluetooth® SMART in order to: