Aplicaciones Tecnológicas launches a new product, the Power Supply Tester AT-3503

Aplicaciones Tecnológicas launches a new product, the Power Supply Tester AT-3503

The new AT-3503 Power Supply Tester of Aplicaciones Tecnológicas is responsible for monitoring and detecting dangerous voltages, network frequency variations as well as increases in the resistance of the earth loop of an installation. The line tester detects any network anomaly by acting through its dry contact relays.

This device also has a screen showing voltages, frequency and impedance in real time. When an alarm sounds the Power Supply Tester AT-3503 indicates it intermittently on the screen and saves the event in your memory for further verification.

This is a very useful tool because if the neutral is cut by a permanent power surge or undervoltage the device will inform you. In the same way, in case the ground or neutral cable is disconnected, the tester will detect and indicate it.

What are the features of the Power Supply Tester of Aplicaciones Tecnológicas?

  • The equipment has two dry contact relays which are activated when a voltage and/or impedance alarm occurs.
  • Can be connected to a three-phase network, either 120Vac (L-N) or 230Vac (L-N).
  • It is self-configurable, which allows it to recognize the type of network it is connected to in the first initiation.
  • Internal memory is capable of storing up to 50 voltage events and 50 impedance events, which can be viewed by browsing the screen.

In addition, the thresholds of overvoltages and undervoltages can be configured by the user.

The default values are:

Type of network




90 Vac   

160 Vac


190 Vac

265 Vac


  • The limit for the impedance alarm is configurable by the user and can vary between 0 and 100 Ω.
  • The default value for this limit is 25 Ω.

How does the AT-3503 Power Supply Tester work?

When the Power Supply Tester determines the type of network and is configured it enters the normal operating mode, where the voltage values of the lines, impedance and frequency are displayed on the main screen.

Once an event occurs, the equipment activates the corresponding relay(s) and alternatively displays the main screen and the display(s) of the events. When the anomaly ceases, the computer keeps the event logged in memory, disables the output and returns to the main screen.

The AT-3503 Power Supply Tester of Aplicaciones Tecnológicas allows you to test the dry contact relays of the equipment to verify they work properly.

It allows three different types of tests:

  • Test 1: activates the output voltage and the output impedance for 15 seconds.
  • Test 2: activates the output voltage for 15 seconds. Output impedance remains off.
  • Test 3: activates output impedance for 15 seconds. Output voltage remains off.

How many records can you save in the memory?

The equipment registers the events so that the user can review them. The Power Supply Tester memory records a total of 50 voltage events and 50 impedance events. You can check the memory status of each event on the main screen.

Technical Characteristics of the Power Supply Tester AT-3503

  • Nominal voltage (L-N) / (L-L): 120 Vac / 230 Vac [ 230 Vac / 400 Vac.
  • Maximum continuous operating voltage: 400 Vac.
  • Nominal frequency: 50/60 Hz.
  • Impedance reading from 1Ω to >100Ω.
  • Voltage variation alert output 120 Vac: programmable, 90 Vac Undervoltage and 150 Vac Overvoltage by standards.
  • Voltage variation alert output 230 Vac: programmable, 190 Vac Undervoltage and 265 Vac Overvoltage by regulation.
  • Impedance variation alert output: programmable, default 25Ω.

What type of installation does it require?

The device must be installed in parallel with the low voltage line, downstream of the power control circuit breaker, with connections to phase, neutral and earth. Installation and handling should be carried out without power in the line.

In addition, it is recommended to always install the equipment together with the appropriate temporary and transient overvoltage protectors.

For more information about the Power Supply Tester AT-3503 from Aplicaciones Tecnológicas S.A, please contact our expert technicians here.