1. Do I need to plug my appliance into iSocket in order to receive power outage alerts and do I need a 'Power Switch' feature?
In order to detect power outages to your appliances (like fridges, pumps, etc.) it is enough that you plug your iSocket to any free wall socket as long as this socket located on the same electrical circuit (powered from the same breaker) with your appliance. You do NOT need to plug your appliance into iSocket, because iSocket detects mains failure - power interruptions in your wall socket. If you do plug your appliance into iSocket you need to turn it on in order to energize your equipment connected into iSocket because internal relay of iSocket is turned off by default. You do this in the 'Power Switches' section.
NOTE! Connecting your appliance into iSocket without real needs you create a so called extra point of failure. For example, occasionally you can turn it off and de-energize your appliance, or you can mess up with thermostat settings and it will be turned off, or internal relay of iSocket will fail and your appliance will be de-energized. Note about relays: they are designed for resistive loads, not for inductive. Some fridges/freezers with pumps will have surges on power on/off events and there will be inductive load that may damage relays. It is not failure of your fridge, neither iSocket. This is how fridges/freezers designed and how relays are designed too. We do NOT recommend to plug fridges/freezers into iSocket directly without real needs.
What is the "real needs" then? Well, say, you don't have any free wall outlet for iSocket on the same electrical circuit that your appliance. If you are going to plug your fridge into iSocket keep in mind that reminder about relays. Another reason why you may want to plug your appliance into iSocket is because you want to switch it on/off/reboot remotely (say, you have a router). This is absolutely fine as these are features of iSocket: remote switch on, remote switch off, remote reboot. So the main reason when your appliance should be connected to iSocket is when you plan to use these features. That is when you need the 'Power Switch' feature.
2. What appliances can I connect into iSocket?
First of all please check the previous question about whether you need to plug anything into Socket at all. For power outage detections you can use Socket on any free wall socket as long as it on the same electrical ring with your appliance. It's better explained in another question.
The internal switching mechanism of iSocket (relay) only supports resistive load. This is a completely normal practice for devices of this class. The opposite of a resistive load is an inductive load. How to distinguish inductive and resistive loads? Inductive load is usually indicated by the presence of a motor mechanism in the device. Examples of inductive loads: pumps, fans, refrigerators. Such devices can damage the switching mechanism of the device (relay) and your device will stop working for this very reason.
You should not create an unnecessary points of failure without extreme needs. That is the core problem of any installation where a customer want to have "a mediator" between the wall and the appliance. If your application is just detection of power outages do NOT plug anything into iSocket, especially when you do not have a feature to switch this outlet on the iSocket - see the previous question.
Also the relay will be off during remote firmware update procedures, which we, however, do NOT perform without customers will.
This explanation might look too tech and not what you usually see from different smart plugs vendors, but this is just because we care. Otherwise principles for all smart plugs are the same - they have a small relay mechanism, which is for resistive load mainly.
3. How can I detect equipment failure?
Appliance failure detection feature relies on the fact of current passing through the relay of iSocket from the wall socket into your appliance. When your appliance that is connected into iSocket draws power from the wall socket iSocket knows it, so your appliance is operating as it is consuming power. Once your appliance is broken it stops consume power and iSocket detects it.
Hence the following limitation on the use of this feature apply. If your device is turning on and off during normal operation then you will never be able to distinguish a breakdown from a normal operation and there is no straightforward way to do this. Take the refrigerator, for example. During normal operation its motor is constantly turned on and off. How can you find out why the refrigerator turned off? Has it broken down or because the motor has turned off?
You may only detect failures of appliances that suppose running on constantly. Note, in order to use this feature you have to order a proper iSocket model with energy meter or select specific applications on checkout. Please read also previous two questions before you plug anything into iSocket.