NOVUS Solid-State Relay SSR 4840AC / 4880AC Instruction Manual
- June 3, 2024
- Novus
Table of Contents
Solid-State Relay – SSR
SSR 4840AC / 4880AC – INSTRUCTIONS MANUAL – V1.0x D
FEATURES
Solid-State Relays (SSR) are electronic devices used to switch resistive or
inductive AC loads with many advantages over conventional relays. A command
signal (INPUT) determines the activation of the load connected to the output
terminals (OUTPUT) without electrical noise, sparking or mechanical wear.
They have a LED, which acts as an on or off status indicator, internal output
snubber, and Zero Crossing function. It turns on at zero Volt and off at zero
Ampere. Optical isolation between INPUT and OUTPUT.
OPERATION
Upon receiving a command signal at its input terminals, the SSR conducts (turns on) and powers the load. When the mains voltage crosses zero, conduction takes place. The same process happens during shutdown. The command signal is removed, but the SSR only blocks (turns off) at the next zero crossing.
This implies delays of no more than 8.3 milliseconds between the instant the
ON/OFF command is triggered and the act of energizing or not energizing the
load.
Switching the load power on and off at a zero crossing has important
advantages for the installation. No electrical interference is generated in
the installation and the SSR is not subjected to severe switching conditions.
It is impossible to switch direct current (DC), only alternating current (AC).
ELECTRICAL CONNECTIONS
2 connections are required: Command signal and connection with the load. When making the connection to the load, you must use an ultra-fast fuse to protect the installation. Well-fixed terminals and adequate wiring help improve the installation efficiency.
HEAT DISSIPATION
SSR generates heat during its conduction. This heat must be dissipated to
avoid SSR fail due to over-heat.
The load current (IL) ratings set for each SSR model consider the use of a
suitable heat sink. Without a heat sink, the maximum allowed load current is
substantially reduced. You can calculate the appropriate heat sink for your
process or use the model indicated by NOVUS.
Where:
R thha = Thermal resistance heat sink to ambient
T amb = Maximum ambient temperature
IL= Load current
V ssr = Voltage drop when the SSR is ON.
75°C is the maximum temperature allowed for the
t these current levels, in addition to the heat sink, forced ventilation is
also critical for maximum performance. Thermal paste, which is essential for
perfect heat transfer, must be used between the SSR and the heat sink. The set
SSR + heat sink should be fixed in a vertical position to facilitate heat
exchange.
Notes:
- The use of the Thermal Pad that comes with the SSR is optional. In installations where a heat sink is provided for the cooling function, you do not need to use the Thermal Pad. In installations where the surface to receive the SSR is not perfectly flat, its use may improve the cooling of the SSR.
- Make sure that the screws on the SSR terminals are properly tightened. Contact problems at these points influence the proper operation of the entire installation power system.
- Before continuous use, always perform installation validation tests.
The graphs below show the current carrying capacity of the SSR as a function of ambient temperature when mounted on the indicated heatsink and whether or not the fan is used.
SPECIFICATIONS
Parameter | Unit | Model |
---|---|---|
SSR 4840AC | SSR 4880AC | |
Load current (IL) | A rms | 40 |
Load voltage | V rms | 40 to 530 |
Voltage drop (Vssr) | V rms | 1.1 to 1.5 |
Leakage current | mA rms | < 8 |
Frequency | Hz | 47 to 63 |
Dv/dt | V/ps | 500 |
12t (50/60 Hz) | Ms | 1770 / 1629 |
Control voltage | V rms | 90 to 280 |
Control current | mA | 5to 10 |
Switching time | ms | < 10 |
Control method | Zero cross trigger (resistive load) | |
Instantaneous (inductive load) | Zero cross trigger (resistive load) |
Instantaneous (inductive load)
Isolation| V rms| 4000| 4000
Housing temperature| °C| -40 to 80| -40 to 80
Plastic body material| UL E211125 / 94 V-0
Metal base material| Aluminium with phosphor bronze coating
Certification| CE
Table 1 – Specifications
DIMENSIONS
WARRANTY
Warranty conditions are available on our website
www.novusautomation.com/warranty.
NOVUS AUTOMATION