Electrical Heater - Emerson Chilled Water Series User Manual

78 Chapter 7 System Operation And Maintenance
pre-fill operation the infrared lamps are inactive, and the humidification is suppressed. In this way, small
quantity of water will be added to the water pan to prevent the damage of the water pan by dry burning.
2. If the off time is less than the default value of the program, the pre-fill program is bypassed and the infrared
lamps and water valve are activated at the same time to fill the pan to the proper water level and initiate
humidification. Small water pan will be filled for 4min, while large water pan will be filled for 7min, and then the
water makeup valve is closed.
During normal infrared humidification operation the water makeup valve is periodically closed (no pan fill)
and opened (pan fill) based on a timing sequence to allow for the evaporation of water from the pan. Water
filling will be triggered for every 8min of humidification (for small water pan) or every 10min of humidification
(for large water pan) to make up the consumed water and flush the minerals floating on the water of the water
pan. The water filling quantity may be set by the customer according to the local water quality.
You can modify the percentage from 110% to a maximum of 500% in 1% increments.
The autoflush system will periodically flush the water pan to prevent the accumulation of sediments because
of erosion effect. Because of the difference of water supply in different regions, the water flowing past the
system shall be set with program to match the local needs. The selectable water quantity is 110% to 500% of
the water flow rate. The autoflush system will operate automatically after water quantity is selected, and no
further adjustment is needed. See Figure 7-4 for humidification control logic.

7.5 Electrical Heater

Check the rust on the electrical heater. If necessary, clean the rust with wire brush, or replace the heater.
The electrical heater is classified into upflow electrical heater and downflow electrical heater, as shown in
Figure 7-5. Three temperature switches are in series connected within the internal control circuit of the
electrical heater, including two auto-reset switches and one manual reset switch. When the electrical heater
does not respond to the heating demand, check if the manual reset switch has been disconnected.
Call for humidification
Note:
HMV: humidifier valve
IFS: Infrared small pan
IFL:Infrared large pan
Figure 7-4 Humidification control logic
Manual reset switch
Manual reset switch
Automatic reset switch
Upflow electrical heater
Figure 7-5 Upflow and downflow electrical heater
Liebert.PEX Chilled Water Series Air Conditioner User Manual
On in last
No
15 hours?
Yes
HMV and
lamps on
4min: IFS
7min: IFL
Humidification
lamps only
8min: IFS
10min: IFL
Downflow electrical heater
HMV pre-fill
IFS: 30s
IFL: 60s
refill
110% ～ 500%
Automatic reset switch