Fan Relay Unit PLCK-USB

Use GrainWatch™ PLCK-USB Fan Relay Unit with outdoor temperature sensor rHS01 and PC Software to control automatic silo aeration. When the trip levels for relative air humidity, air temperature and grain temperature set in the software are triggered, the fan relay unit starts the aeration process automatically.

The GW-PLCK-USB Fan Relay Unit is available with 4, 10, and 26 relay outputs, and connects to the PC via two USB ports.

The vital condensation sensor part of the unit is patented (SE529584).

About Grain Aeration

Grain Aeration is a process where small portions of air are blown through the commodity,  to cool and ventilate, thereby guarding the quality. It is important to remember that grain moisture is changed very little by aeration. This due to the low volumes of air used in the process.

Aeration should never be confused with grain drying, which is a process to rapidly reduce moisture to a desired level for storage and delivery.

Grain temperature, air temperature and relative air humidity are vital checkpoints in the aeration process. Distributed air warmer than the stored grain, means raising the grain’s moisture content and temperature. A serious risk for dimished commercial value.


Use the data table as follows:

The data table indicates air humidity in percent RF%. Principle: Cooling Air Temperature and Grain Temperature coinciding on a blank spot = no risk of raising the grain’s moisture content. Coinciding on a number spot = relative air humidity must be lower than the number. The latter to avoid raising the grain moisture content.

Grain-Watch PLCK-USB Fan Relay Unit table indicates air humidity in percent RF%.

Source: Lantmännen, Safe Grain Storage.