RDZ UMHPI, User Manual

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UMHPI
Industrial inverter air/water heat pumps with axial fans
13
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P10 : Delta modulating pump (°C)
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In cooling mode: Δ T= [Water inlet temperature] – [Water outlet temperature]
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In heating mode: Δ T = [Water outlet temperature] – [Water inlet temperature]
Example in cooling:
If the difference in temperature between water inlet and outlet is greater than
P09 + P10 , the pump will run at maximum speed.
If the difference temperature between water inlet and outlet is less than P09 - 0.2°C , the pump will run the minimum speed.
In the other cases, the pump modulates trying to match the temperature difference with P09 . For the heating mode, the same
considerations are valid with replace only P06 with P09 . Please see paragraph 11.6 for changing the parameters.
Warning: During the DHW production mode, the pump is constrained to operate at its maximum speed.
In domestic hot water production mode, the pump will operate at the maximum speed.
7.4 MULTICOMPRESSORS
In case that multiple compressors operate, the adjustment will be done by turning on the first compressor according to the
deviation of the water temperature from the set.
The selection of which compressor that must startup first occurs according to the technique based on the equalization of the
cumulative hours of operation.
The control logic is to have the compressors operating at a frequency near the thermoregulation capacity threshold for to activate
the second step
b17 and the nominal HzMaxReg calculated in the different conditions of the water and air temperatures as a
function of the mode of operation.
The activation of the second step will occur only if the frequency of the operating compressor is included between these two
values. It makes sure that only one compressor follows the variations of the thermoregulatory, the other is maintained at the
HzMaxReg .
7.4.1 LOGIC OF ACTIVATION
If the controller regulates all the modulating compressors in operation for to provide a capacity greater than the nominal value for
a continuous time duration equal to
b16 seconds, the activation of a further available compressor is required. In case of
unavailability of activation of any compressor, it could also be due to the logic related to the capacity limitations or to the
compressors protection (see envelope paragraph).
For each activation of a new capacity step, the compressors already in operation pass to the minimum operating speed for a
duration of
b19 seconds. Please see paragraph 11.6 for changing the parameters.
7.4.2 LOGIC OF RELEASE
If the controller regulates one or more modulating compressors (in operation) for providing the minimum capacity for a period of
time greater than
b18 seconds, the compressor will stop operation.
When the release has occurred, you should wait again for a timer period equal to b18 seconds before releasing the capacity step.
Please see paragraph 11.6 for changing the parameters.
WARNING : In the case in which the regulation temperature is found to be lower than Set - b05 , the release of the running
compressors occurs sequentially with a minimum time delay between two commutations given by parameter C04 , and not
following logic described above.
7.4.3 CAPACITY CONTROL
The regulation of the delivered capacity is always made by only one of the running compressors; the best is to control the
compressor that is not running at minimum or nominal capacity. If there is no compressor running at minimum or nominal
capacity:
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The requests of capacity increasing will be done by selecting among the whole running compressors at the minimum
capacity. The selection will consider the one with lower hours number of operation.