Reheating During Dehumidification - Emerson Liebert iCOM Training And Service Manual

iCOM
Controls Training and Service Manual

Reheating during Dehumidification

The parameter Electric Reheat Operation defines how the reheats react when the
return air temperature decreases below the temperature setpoint during the
dehumidification process. The following are the selections:
Selection
No electric reheat allowed during compressorized dehumidification
No
operation.
If normal reheat control is selected, the reheats are turned ON at the
normal points of 33%, 66%, and 100%. If the temperature drops to
Low Limit 1 then 1 compressor is temporarily disabled (the
dehumidification request is reduced to 50%). It is re-enabled when
the heating requirement is decreased to Low Limit 1 reset value. If
Normal
the temperature drops to Low Limit 2, both compressors are
temporarily disabled (the dehumidification request is reduced to 0%).
One of the two compressors is re-enabled at the Low Limit 2 reset
value.
When 1 compressor dehumidification and delayed reheat is selected,
the reheats are turned ON at the normal points of 33%, 66%, and
100%.
On 2 compressor dehumidification all three stages of electric reheat
are OFF until the return air temperature falls to Low Limit 1, then 1
Delayed
stage of dehumidification is disabled and all three reheats are
activated. If the return air temperature falls to Low Limit 2, both
stages of dehumidification are disabled. One stage of
dehumidification will be re-enabled at the Low Limit 2 reset value.
Both stages of dehumidification are re-enabled at the Low Limit 1
reset value.
Warning:
Dehumidification with normal reheat allows for operating both compressors and all
reheat stages simultaneously. It is very important that the electrical service to the
unit be sized and wired for this option if selected. If not sized properly the
electrical service could experience nuisance trips and or possible damage to
building circuit breakers (or Fuses) and wiring.
Operation
34