OXAVAR PROVAP® 220

01 · WORKING CYCLE

Two minutes of warm-up, then one hive every twenty seconds

You plug it in, it climbs to 230 °C in about two minutes and it stays on all day. Load the pan with the dose levelled off with the spoon, turn the unit over and insert it straight away. As the cold acid goes in, the plate drops to 210-215 °C: sublimation happens during that fall, and when the reading climbs back to 230 °C that hive is done.

02 · THE 230 °C QUESTION

The display reads the empty plate, not the acid

It is the question that comes up most: if oxalic acid sublimates from 157 °C and starts to break down above roughly 189 °C, why does the unit read 230 °C? Because that figure is the empty pan before you load it. A plate sitting at exactly 157 °C would have no heat in reserve to sublimate a dose in twenty seconds: it would cool on first contact and the cycle would stretch into minutes. The surplus is what gets spent heating the acid, which is why the reading falls as you load. What matters is not the peak of the empty plate but how long the product stays in contact with it, which here is seconds.

03 · POWER AT THE APIARY

Inverter generator and a short lead

It needs 1,000 W as a minimum, and inverter; above that power there is no problem, below it there is. A conventional set puts out dirty waveform and this unit carries control electronics. And one rule that gets overlooked: no more than 10 metres of cable from the generator. The voltage drop over a long lead does not just heat it less well, it can damage the unit.

04 · MAINTENANCE

Clean the pan at the end of the day

This model does not clog if you clean it; it clogs if you do not. At the end of the day, with the unit still switched on, add a little water to the pan and the residue lifts off by itself. Doing it hot and doing it daily is what stops a blockage mid-season. It comes with two pans, so you can swap one in while you clean the other.

05 · BEFORE YOU BUY

You work crouched at the hive entrance, and over a long run of hives that posture costs you more than the seconds you save: that is what the version with a steel bar and top loading is for, which is worked standing. And on very large apiaries, chaining doses without a pause means the element takes longer to recover and the rhythm drops.