EVCO c-pro nano HPR0 - Manual (Page 25)

C-PRO NANO HPR0 APPLICATION MANUAL
Page 25
5.10 Flow switches management
The 2 unit flow switches are managed separately: heating/air conditioning circuit, geothermic
circuit, but the setting of the “Flow switches alarm delay” is unique for the two flow switches.
On expiry of the Flow switches alarm delay time, if the contact signals no flow, the alarm is given
immediately, stopping the pump and preventing compressor switch-on.
During normal functioning, the flow sensor is monitored continuously: if the contact signals no
flow for a period of time exceeding the delay, the alarm is given immediately, switching off any
compressors that are functioning.
The flow switch alarm has manual reset using the front key of the controller.
5.11 Management of high pressure alarm from pressure switch
Via the digital input D/I 1, connected to the mechanical HIGH pressure switch, it is possible to
intervene when a maximum pressure in the cooling circuit is exceeded. With the high pressure
alarm , compressor 2 is stopped and, with the persistence of the alarm, after a certain period of time
(that can be set by parameter PC10) compressor 1 is also stopped (stop unit). The alarm has manual
reset using the front key of the controller.
5.12 Management of low pressure alarm from pressure switch
Via the digital input D/I 2, connected to the mechanical pressure switch, it is possible to intervene
when a minimum pressure occurs in the cooling circuit intake. The low pressure alarm causes the
immediate shutdown of the cooling circuit, stopping any compressors running and preventing others
from switching-on.
On start-up of the first compressor, the alarm is delayed by a certain time (that can be set by “LOW
pressure delay” PA03), so as not to allow the compressors to pressurise the circuit. The alarm has
manual reset using the front key of the controller.