Reece Fitzhardy tries out the MAINSLINK-PRO two-remote switching system from RF Solutions.
In simple terms, the MAINSLINK-PRO is a bi-directional radio switch which replaces two ‘switched live cables’, thus removing the need to lay hard wires. This is particularly useful when situated between a boiler and the wiring centre – one of the key applications for the product.
Upon opening the box, I found that the switches arrived as a paired linked system, with each switch having a mains input and switched input and output. I believe they’re arranged in this way so as to provide a remote cross-coupled mains switch.
To explain this further, essentially switch ‘A’ will have input and output. The input to switch ‘A’ will then drive output from switch ‘B’, and the input to switch ‘B’ will drive output from switch ‘A’. Power is then limited by relay contacts and a 4A fuse.
So how does it work?
The specific design idea for the MAINSLINK-PRO is as a remote Worcester Bosch boiler link between the timer/thermostat and boiler. However, upon further investigation, it is clear that many other applications are possible, including the control and switching of lower power LED lights.
If we look at its use with a Worcester Bosch boiler, one unit is installed by the boiler and the other within the wiring centre. Each unit then has a ‘Live in’ and a ‘Live out’ screw terminal which use RF signals to communicate with one another. This is aided by the use of RF Solutions’ RF-LoRa spread spectrum frequency hopping transceiver, which is designed to offer a high radio link range and performance.
The photo of the link unit in this article shows a fairly congested situation (I included a terminal block for this test scenario) but, in practice, the cable layout will be clearer. That said, cable sizes shouldn’t be any larger than 0.75mm flexible as there is a space limitation in the boxes provided. I’ve ‘tinned’ my cables, but ‘bootlace’ crimps would likely prove more useful.
Care is needed inside this box as the terminals are directly on the electronics PCB. In addition, various ‘jumper’ links are present, which can be used to configure the following:
WDOG – WATCHDOG
This is a regular link check between the paired units. If the WDOG signal isn’t received within 90 seconds, the output will drop out and an LED light will flash.
This is a delay for switching, with Mode 3 providing faster operation over a shorter range, and Mode 7 offering slower operation over a longer range.
MOM/LAT – MOMENTARY OR LATCHING
This sets the relay changeover contacts to operate as ‘Momentary’ or ‘Latching’.
These options are all very useful to the user, and I really like the Watchdog concept as it can quickly draw your attention to any communication issues. The only drawback of this monitoring system is that it can’t be viewed from the front of the unit, so the unit will require removal for you to check any status LEDs.
After discussing this with the manufacturer, they’ve advised that they’re in the process of upgrading the product with a new enclosure so the LEDs can be seen through the front of the unit, as well as providing extra space for the wiring. This will be released later in the year.
Additionally, the PCB inside is always live, so means of local isolation (either plugs or switched spur) need to be provided.
For more advanced use, it’s incredibly easy to pair two MAINSLINK-PRO units, and a supporting instructional PDF will help you with this. Furthermore, erasing and pairing units up again is also a very simple process.
So how did it perform?
I should state this product does require the user to read through and fully understand how to get the best from it, but the fact that it is supplied ready to go is a major bonus. It is also very easy to install.
Although the specification for distance is a 5Km range in line of sight, and 1Km through buildings, mine was tested in a domestic external building environment with a 30m distance. I’m pleased to say that operation was perfect and I’m looking forward to trying the product out on other applications in the future.