Humidifier Electronics Module - AGFA Avantra 36/44 Service Manual

The humidifier system is closed loop. The inlet port receives drum air, which passes
through an air filter. The system then draws the filtered air through a water wick
whose bottom section is immersed in water contained in an internal resevoir. Next,
through the process of capillary action, the water draws up and saturates the wick.
A float switch controls the reservoir's water level. At a predetermined level of 1.25
inches, the float switch opens. A signal goes to the control electronics and the
water solenoid valve closes. The solenoid valve mounts on top of the humidifier.
Normally, the valve is closed and only opens when the reservoir requires water.
A 24 VDC fan draws the air through the filter and wick. The fan delivers up to 150
CFM (cubic feet per minute) unrestricted free air flow. Fan speed varies in relation
to the amount of humidity required to reach 50% (±5%) relative humidity in the
drum.
Once moisture laden, the air travels via the output port to the drum.
2.15.2.1 Water Supply
The water supply sub-assembly described below consists of the following:
• A sheet metal mounting plate/enclosure and cover
• A water reservoir
• Three feet of 1/8 inch clear tubing
• Two quick connect couplings
The water supply consists of a frosted vinyl water bag having a pop off spout for
filling. The water reservoir (bag) holds approximately 2/3 gallon of water. This
amount represents a three day supply minimum.
The reservoir sits in a holder mounted to the outside (left) of the imagesetter enclo-
sure. A decorative cover, painted to match the imagesetter enclosure, surrounds the
holder and reservoir. A window in the reservoir cover looks in on the water supply.
The water supply connects to the humidifier via a 1/8 inch inner diameter clear
plastic supply line. The tube attaches to the bottom of the water bag and passes
through a small hole in the imagesetter enclosure. Inside, the tube is dressed along
the enclosure's inner wall and down to the humidifier sub-assembly.
The tube attaches to the solenoid valve using a quick connect coupling. On the
opposite side of the solenoid, another coupling with a six inch section of tubing
supplies water to the internal reservoir.
2.15.3 Humidifier Electronics Module
The electronics module monitors and controls the level of moisture in the drum and
adjusts the air flow through the system by varying the speed of the humidifier's fan.
This module also controls the on/off function of the water solenoid valve in
response to the float switch.
Section I: Imagesetter
Functional Analysis 2-35