ZSLC Series

  • Features
  • Details
  • Type Overview


Voltage up to 600 VZSLC Serie
Current up to 2,500 A
Power 8,000 W ... 40,000 W
• High power density by liquid cooling
Minimal operating noise
• Temperature controlled coolant circuit
Condensation protection
For coolant with up to 30% glycol
Current, voltage, resistance, power mode
Dynamic loads
SCPI programming with measurement function
Electronic protection
Analog measurement outputs for voltage and current
Analog control input
Dynamic function with synchronized data logging


Operating Modes
The ZSLC series electronic loads have the four operating modes constant current, voltage, power and resistance. In addition, depending on the operating mode limit values can be set for the maximum permissible current and the minimum permissible voltage. To increase the resolution for each device, along with the full setting range, a reduced setting of 1/3 of the rated current is available. The load can be preset even without a connected test unit. The display then shows the values directly in amps, ohms, volts or watts.

Dynamic and Control Time
The inbuilt modulator enables two independently adjustable currents and times from 100 μs ... 1 s. The control speed of the devices can be adjusted to the test unit in three stages (fast - medium - slow).

Protective Devices
The following protective devices are built in:

  • Over-current protection
  • Over-power protection
  • Over-temperature protection
  • Protection of the GND lines on the Analog I/O interface

Voltage Switching
A trigger voltage can be set for peak-free voltage hook-up. The current is enabled when the input voltage exceeds the trigger voltage.

Overload Capacity
Depending on the model the devices have temporary overload capacity. The level and duration of the possible overload depends on the operating temperature of the output stage. The device can therefore be used for significantly higher performance tasks.

Remote Control
Most load functions can be controlled remotely via Analog I/O Interface. The control inputs can be operated with TTL levels and 24 V from PLC controllers.

A version (ZS06) which is electrically isolated from the load input is optionally available.

Analog Control
In the operating modes CC, CV and CP the setting value can be controlled by 0...5 V or 0...10 V DC.

Analog Measurement Outputs
There are 0...10 V analog  measurement signals available for voltage, current and power. The GND terminals can float ±2 V with respect to the negative load input (also optionally isolated - Option ZS06).

Water Cooling
Water cooling is a very efficient heat dispersion method which does not heat the environment. It is also very quiet. The use of water-cooled devices is therefore particularly suited for areas in which corresponding high-performance air-cooled devices cannot be used because of their thermal load and noise. The devices are also considerably more compact.

The coolant must have a pH value of between 6 and 8. A glycol portion of 20% to 30% is permissible. Coolant consumption is controlled according to power. Coolant feed is switched off in standby mode. The maximum coolant temperature for the rated power is 12 °C. Power derating should be considered at higher temperatures. A corresponding lower coolant quantity is needed at inlet temperatures of less than 12 °C. To ensure that the device is fed with sufficient coolant it requires an operating pressure of 3 bar at the inlet. Drainage must be possible without creating back pressure. The required flow rate can be found in the type overview.

Condensation Protection
The ZSLC devices are protected against condensation of liquid by cold coolant.

The ZSLC is a sturdy 19“ rack design and can also be used as a table-top device.

From 5 height units there are retractable handles on the top of the device.
Optional castors can be mounted on heavy devices. No separate installation kits are needed for 19“ rack installation.

All connections are at the rear side. The current connections are solid copper rails with screw connectors.

Covers are available as contact protection for units for dangerous contact voltages.

Interfaces (optional)
  • RS-232 + USB
  • GPIB
  • Ethernet-RS-232 Converter
  • System Interface Cabel or Fiber Optic
  • Data Acquisition Tool

Hardware Expansions (optional)
  • Electrically Isolated Analog I/O Interface
  • Power I/O Card
  • Analog I/O Extension-Card
  • Temperature Interface
  • Castors
  • Zero-Volt Option

Factory Calibration Certificate
A Factory Calibration Certificate (FCC) can be supplied with the devices. The FCC meets the requirements according to DIN EN ISO 9000ff. This calibration certificate documents the traceability to national standards to illustrate the physical device in accordance with the international  System of Units  (SI). The recommended calibration interval is 2 years.

Software Tools
The H&H Homepage has a program library for Windows with a controll tool an LabVIEW drivers.

We supply a User Manual as pdf file and printed General Safety Instructions, each in German and English.

Type Overview