VDH Products PROBA, Инструкция по установке и эксплуатации

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VDH Products BV Document 063319 - version 3.12 Page: 39 of 78
4.5.1 Sensors for air temperature regulation
With this method of temperature control the ripening room is divided in three zones. The temperature within each
zone is regulated separately and takes place on air temperature (see Appendix B; page 44).
Although the function of each sensor is free programmable, the following configuation is used most:
The sensors 1, 2 and 3 are located in zone 1 (at the back of the ripening room). In zone 2 (in the middle of the
room) sensors 4, 5 and 6 and in zone 3 (just behind the door) sensor 7, 8 and 9 are located.
The PROBA110 uses the sensors 1, 4 and 7 for regulating the temperature. These sensors have to be placed in
the air flow which exits the product (or enters the evaporator).
The other sensors (2 and 3 in zone 1, 5 and 6 in zone 2, 8 and 9 in zone 3) are placed in the air flow which comes
out of the evaporator. These sensors serve for warnings and alarms (temperature too low or too high).
The temperature sensors SM8300 (Pt1000, Class A), can be connected directly to the PROBA110 .
4.5.2 Sensors for product temperature regulation
This method of temperature control resembles the way the predecessor of the PROBA , the BA192 , regulates the
temperature. Although the function of each sensor is free programmable, the following configuration is used most:
It makes use of a maximum of seven (but mostly three) product sensors which are placed in the boxes with
bananas. The connection of these product sensors (type
SM8500 , Pt1000 class A) to the PROBA110 is made via
the coiled leads and the connection box type 502 (see Appendix A; page 43).
The cool and heat functions of the three zones is driven simultaneously (unless one or two zones are switched off;
see 'Number of Zones' page 24, 67).
The temperature which is used for regulation is the average of the present and 'active' control sensors. The present
but 'non active' sensors are not used by the
PROBA110 for determining the average temperature.
Next sensor 8 and 9 are often connected to monitor the air temperature coming out of the evaporator. If sensor 8 or
9 measures a temperature below or above the alarm levels, the cooling or heating is switched off until the
temperature comes within the alarm levels.
As alarm sensor the SM8000/2m (Pt1000, class A) is used, which can be connected directly to the PROBA110 .
4.6 Gas concentration sensor
When using the gas concentration sensor, it is necessary to obtain a good spread of the ethylene gas in the ripening room.
Do not place the sensor near the inlet of the gas into the ripening room.
The sensor has to be mounted vertically; the opening of the black tube facing downwards. Take care not to place the sensor
in the full flow or air. The red mounting bracket is included for mounting on the wall. It is not needed in case the sensor is
placed on the ceiling.
For steady operation over a long period, it is better to have a sensor supplied. This means that the PROBA110 should only
be switched off by the key switch into OFF position. In that case power remains supplied to the gas concentration sensor.
The connection between the gas concentration sensor and the PROBA110 is made with a three conductor cable. It is
recommended to use a shielded cable. Connect the shield to the ground in the PROBA110 and not to the shield of the
network cables !
Inside the PROBA110 the cable is connected to the three terminals (on the
middle left of the relay board), which are marked with ' + ', ' GC ' and ' - '.
The sensor receives its supply voltage from the PROBA110 and returns a signal
of 4 - 20 mA.
The three terminals have the following functions:
+ supply for the sensor (12 - 17 Volt DC)
GC signal from the sensor (4 - 20 mA),
-
return for supply and signal.
Appendix I (page 68) shows the connection diagram of the gas concentration
sensor
PGS2000 itself.
The supply line of the gas concentration sensor is short circuit proof.
To ensure a good and reliable operation of the PGS2000 , it is advisable to have
the sensor calibrated once per year.