Technical Manual Cold Storage Controller EVP 3150-1 and EVP 3150-2
Page 13
ein
aus
ein
aus
ein
aus
aus
ein
aus
ein
2
1
defrost starts
defrost ends
cooling
limitation temp.
evap. temperature
defrosr
Interval fan
electric heater
permanent fan
electric heater
interval fan
airflow defrost
fan off delay
1. pause after defr.
(drain time)
2. fan start
delay
Evaporator Fan Control
Each output relay can be configured for evapo-
rator fan control. The fan control depends on the
following parameters:
P03
..... (cooling mode, Mode Page)
"
reF
" = refrigeration, fan will be switched
by the N/O-contact of the fan relay
"
FrE
" = freezing, fan will be switched by
the N/C-contact
P02
.... (fan operation, Mode Page), defines
the characteristic of the fan during the
cooling period.
"
Int
" = fan runs together with solenoid
valve/compressor
"
PEr
" = fan runs continously while
cooling
"
Add
" = Using of latency heat by a special
fan c "Special mode for room
temperatures > 2,5°C", as described in
chapter "Intelligent Defrost".
d01
.... (fan during defrost, Defrost Page),
defines the fan characteristic during
the defrost cycle.
"
on
“ = during defrost, fan runs
continuously
"
off
“ = fan is stopped during defrost.
Fan operation modes, defrost termination using electric heaters
Fan start-up (freeze-on) delay
The start-up time delay for the fan after defrosting
is defined by parameter "
r22
" (Setpoint Page).
This avoids that water drops will be blown into the
chamber. "
L35
" (Actual Values Page) show the
remaining time up to the fan will switch on.
Examples for fan operation modes
1.
fan in permanent mode
This mode is mainly used in refrigerated
shelfs, refrigerated display counters and
chest freezers
● fan is directly connected to mains voltage,
not connected to the controller unit
or
● a relay is reserved for fan control, "
P02
" is
set to "
PEr
", "
d01
" is set to "
on
".
Drain-time "
d35
" is set to "0".
2.
fan interval mode, defrost by fan
A relay is reserved for fan control, "
P02
" is
set to "
Int
", "
d01
" is set to "
on
".
3.
fan interval mode, defrost by electric heater/
hot gaz:
A relay is reserved for fan control, "
P02
" is
set to "
Int
", "
d01
" is set to "
oFF
". The fan
runs while cooling is on, will be disabled
during defrost periods and comes on after
defrost with a time delay set by parameter
"
r22
".
4.
fan in permanent mode and defrost by
electric heater
A relay is reserved for fan control, "
P02
" is
set to "
PEr
", "
d01
" is set to "
oFF
".
The fan will run continously and stops during
a defrost period only.
Chances to exploit Latency Heat
1. Fan operation mode P02 = "Add"
- If temperature falls, cooling and fan will
stop with reaching the control setpoint.
If the room temperature rises to a value
equal to
Control Se 1/2 Hysteresis
,
the fans restart under the condition that the
temperature of the evaporator (detected
with limitation sensor) is lower than
Control Setpoint - 1/2 Hysteresis
.
So remaining coldness will be blown into the
room which reduces the number of
compressor starts.
- Evaporators can be de-iced already at
temperatures from 2°C by forced air.
When cooling stops, fans are turning on until
ice and frost are melted (limitation calculated
within 2...5°C, cooling switches on at -3K).
Thus humidity stays in the chamber which
will improve the quality of certain goods like
meat or vegetables.
Additonally to the compulsatory "
fan trailing
delay
" (
r23
, fan is forced to continue turning
after cooling reached the setpoint and stopped),
the fan will turn from a specific temperature
[se hysteresis => +2,5°C] until the
evaporator sensor has reached a certain
value.
At room temperatures [shysteresis
=> +2,5°C] notify to set parameter "
d05
" to
a higher value, because a defrost start is
forced if this time is past.
2. Fan trailing delay
To utilize latent energy, the fan is able to run
for up to further 30 minutes after the cut-off of
valve or compressor ("
r23
", Setpoint Page).
M
L
M
L
cool. relay
fan relay
cool. relay fan relay
refrigeration
freezing
