Carel plug-in PJ32C, Руководство пользователя

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Cod. +030221881 rel. 1.0 - 11/02/2000 24
operation according to the standards in force. The electronic control on its own can not be used to guarantee safety in the event of
serious alarms.
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$ = 2: HQDEOHGHIURVW
An external contact can be connected to the multifunction input to enable or inhibit the defrost function. When the contact is open,
the defrost is inhibited, while it is enabled when the contact is closed. If the contact is closed and there is no request from the
controller, obviously the defrost is not performed. If the contact is closed and a defrost is in progress, opening the digital input
immediately stops the defrost and the unit returns to the normal operation (without performing the dripping phase). Upon request
for a defrost the corresponding defrost LED starts to flash, until the next enabling action (closing of the contact). This function is
useful, for example,, in the case of multiplexed showcases with hot gas defrost. These systems must be defrosted by island and
thus, at any one moment, some islands are enabled for defrost, while others are inhibited. Another use of the function is to prevent
defrosting the units available to the public during opening hours. Any defrost requests when the contact is open will stay on hold
until the closing of the contact.
$ = 3: VWDUWGHIURVWIURPH[WHUQDOFRQWDFW
This function allows the defrost to be started from an external contact. If the defrost is started using an external contact, all the type
’d’ parameters selected are valid. In particular, it may be useful to set
G,=0 to enable manual defrosts or defrosts from external
contact only, excluding defrosts generated by the internal clock.
This function is useful in the case where
UHDOWLPHGHIURVWV are required. To perform these, simply connect a mechanical or
electronic timer to the digital input. When the contact of the timer moves from open to closed it enables the defrost request.
It may be the case, as mentioned in the description of parameter
G, that more than one unit is connected to the same timer.
Selecting a different value for
G for each unit will avoid simultaneous defrosts.
:DUQLQJ: the minimum duration must be 0.5 seconds.
Key:
W = impulse from the timer to start the defrost;
G3 = maximum defrost duration, unit 1;
G = defrost delay from external contact for unit 2. This
must be greater than
G3(1), to avoid defrosting at the same
time.
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$ = 4: FXUWDLQVZLWFKQLJKWWLPHRSHUDWLRQ
Setting parameter
$ =4 manages the contact which signals the closing of the curtain on showcases or modifies the set point for
night-time operation. With the contact closed the Set Point is modified by the value
U (Set Point variation for night-time
operation).
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YDOXHSDUDPHWHU$ PHDQLQJ 6 < ; &
0 input not active
♦ ♦ ♦ ♦
1
external alarm instant or delayed (
$) ♦
-
♦
-
2 enable defrost (closed = enabled)
♦
-
♦
-
3 start defrost on closing
♦
-
♦
-
4 curtain switch or night-time operation
♦
-
♦
-
7DE
:DUQLQJ: parameter $ is accessible on all models, but can only be used on those which effectively have the input, in alternative
to the second probe. When the input is not present, the value of
$ must be zero (0), indicated by the – (dash) in Tab. 4.8.2.
t
timer
defrost
defrost
dP(1) unit 1
dP(3)
unit 3
d5(3) defrost
dP(2) unit 2
d5(2)
defrost request