RDZ UMHPI User Manual Download

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UMHPI

Industrial inverter air/water heat pumps with axial fans

Before proceeding, the equation must be: in continuous mode, fulfilled or unfulfilled respectively for

v11

minutes

(fulfillment) and

v12

minutes (unfulfillment). At the power-on, the unit turns on with unfulfilled equation.

7.16.3

Vapor injection valve (VEIV)

Even after the fulfillment of one of the two equations (Eq.1 or Eq.2) the VEIV valve must remain closed until the below condition is
met also:

(Eq.3) DSH >

v13

Before proceeding, the equation must be fulfilled or unfulfilled, in continuous mode respectively

v14/v15

minutes (fulfilled) and

v16/v17

minutes (unfulfilled).

After the condition fulfillment, the valve will be managed following the superheating given by:

−

ISH

(superheating of vapor injection) =

(detected) -

(resulted)

The recognition of the situation of the preconditioned unfulfillment DHS value will close the VEIV valve. At the shutdown of the
whole compressors the VEIV valve will be closed and the above control logic will resume only after their re-ignition.
In the case of multi compressor systems in addition to the VEIV valve, each compressor will have its own ON/OFF valve to allow
the vapor injection only when the corresponding compressor is turned on and not only to the fulfillment of the above conditions.
The valve that enables vapor injection will turn on only when the compressor is switched on for at least

v18

seconds and the

injection is active.

•

Initial steps

: Set the number of initial steps of the valve. At the first opening of the valve, the superheat control is bypassed

for Pa

v18

seconds and the valve positioned with this initial value. After the end of

v18

seconds the superheating control

will be activated.

•

Control algorithm of the vapor injection valve

: The control is of the PID type (proportional/integral/derivative) operates on

the process variable ISH. The valve opening may vary between the maximum (

v22

) and the minimum steps (depending on

the operating mode).

ACTIVABLE LOGIC FUNCTIONS WITH GI- MODULE FOR PLANT MANAGEMENT (optional)

Wherever the GI optional plant management kit is present, there is a second controller located inside the electrical board that acts
as expansion module of the I/O resources. With this second controller (SL1), it is therefore possible to increase the number of logic
functions managed by the main controller; in particular, these logic functions are used for management the plant, as we described
below. The following functions can be activated by the controller of the Master unit which is located on its front panel.

8.1

AUXILIARY ELECTRIC HEATERS

In some plant systems configurations, it could be necessary the use an auxiliary electric heater for the system and/or DHW sides.
To define the mode of using of the auxiliary electric heaters for plant system and DHW side, you must set the parameter “

r24”

below

r24=0

Auxiliary electric heaters not used;

r24=1

Utilization only of the auxiliary electric heater of the plant side;

r24=2

Utilization only of the auxiliary DHW electric heater;

r24=3

Utilization of both auxiliary electric heaters of plant side and of domestic (sanitary) hot water production.

To change the parameters, please see paragraph 11.11.

8.1.1

AUXILIARY ELECTRIC HEATER THE PLANT SYSTEM

In some configurations of plants, the use of an auxiliary electric heater for the plant system side could be necessary.
If the temperature of regulation remains below the

water setpoint in heating (Hea) - 0.5°C

for a period of time equal to

r12

, the

auxiliary electric heater will be activated depending on the in joint or in substitution operation of the unit indicated in Paragraph
8.2. The electric heater turns off after reaching the setpoint (taking into account of an eventual offset set with the parameters

r29

r30

(check Paragraph 8.3.6).

If the temperature of regulation remains less than

water setpoint – r11(°C)

and the unit is blocked that is caused by an error-

alarm, the electric heater will be activated. Then it will turn off when the lock-alarm is resolved.

To activate this function you should set the parameters

CnF

and

by getting access with the service password:

Parameter