Emerson XM678D - Page 59

MODBUS Termination Blocks Default Parameter Map • 51
rPE 100
Virtual probe
percentage
(roo
m temperature)
0 to 100%
Defines the percentage of the rPA with
respect to rPb. The value used to
regulate the room temperature is
obtained by:
value_for_room = (rPA*rPE +
rPb*
(100-rPE))/
100
DEFROST
dPA P2 Defrost probe A
nP(0); P1(1); P2(2);
P3(3); P4(4);
P6(5)
First probe used for def
rost
. If 
[dPA = nP], th
e regulation is performed
by time.
dPb nP Defrost probe B
nP(0) - P1(1) - P2(2) -
P3(3) -
P4(4) - P5(5)
Second probe used for defrost. If 
[dPb = nP],
the regulation is performed
with dPA.
dPE 100
Percentage of the
first defrost probe
0 to 100
(100=dP
A, 0=dPb)
Defines the percentage of the dPA
with
res
pect to dPb. The value used to
regulate room temperature is obtained
by:
value_for_defrost= (dPA*dPE +
dPb*
(100-d
PE))/100
tdF EL Defrost kind EL; in
EL = defrost with electrical heater
in = hot gas defrost
NOTE: The valve openi
ng percentage
during th
e defrost is set by the
parameter oPd.
Srt 302
Heater setpoint
during d
efrost
[-67°F to 302°F]
[-55.0°C to 150°C]
If td
F=EL during the defrost the defrost
relay perform an ON/OFF reg
ulation
with Srt as set point.
Hyr 4
Differential for
heater
[1°F to 45°F]
[0.1°C to 25.5
°C]
If the defrost probe temperature is
bigger th
an Srt for all tod time, the
defrost ends although the defrost probe
temperature is lower than dtE or dtS. It
permits to reduce defrost duration.
tod 255 Time out for heater 0 to 255min
If the difference between the two
defr
ost probes stays lower than dtP for
all ddP time the defrost is activated;
dP2 n
Defrost with two
prob
es
n(0) – Y(1)
n= only the dPA probe is us
ed to
defrost management; Y= defrost is
managed with dPA probe and dPb
probe. Defrost can performed only if
both probe value are lower than dtE for
dPA probe and dtS for dPb probe
dtE 46
End defrost
temperature on
probe A (dPA)
[-67°F to 122°F]
[-
55.0
°C to 50.0°C]
Set the temperature meas
ured by the
evaporat
or probe dPA which stops the
defrost. Parameter enabled only when
the evaporator probe is present.
dtS 46
Defrost termination
temperature
(Probe B)
[-67°F to 122°F]
[-
55.0
°C to 50.0°C]
(Enabled only when the evaporator
probe is presen
t) Sets the temperature
meas
ured by the evaporator probe dPb
resulting to end of defrost.
Label Value Description Range Notes
Table 24-1 - Default Parameter Map