7
Human-Machine Interface
The control has a graphic display that allows the following
information to be displayed:
•
water inlet and outlet temperature
•
set temperature and differential set points
•
description of alarms
•
hour meter of operation and number of start-ups of the
unit, the compressors and the pumps (if present)
•
high and low pressure values, and relevant condensing
and evaporating temperatures
•
external air temperature
•
superheating at compressor suction.
CONTROLS AND SAFETY DEVICES
All the units are fitted with the following control and safety
components:
•
high pressure switch with manual reset
•
high pressure safety device with automatic reset, for a
limited number of occurrences, managed by the con-
troller
•
low pressure safety device with automatic reset and
limited tripping managed by the controller
•
high pressure safety valves
•
antifreeze probe at the outlet of the user-side heat ex-
changers
•
differential pressure switch already fitted on the us-
er-side heat exchangers
•
overtemperature protection for compressors and fans
TESTING
All the units are factory-tested and supplied complete with
oil and refrigerant.
PACKAGING
The unit is made and shipped on a wooden pallet that al-
lows the unit to be handled using a forklift truck.
The unit is wrapped in a protective transparent polyethyl-
ene stretch film.
VERSIONS
Zeta Rev HE FC/NG
In addition to the components of the basic version, the /
NG set-up unit has:
•
a water/water decoupling plate heat exchanger in place
of the 3-way valve
•
a circulation pump dedicated to the free cooling circuit
(closed circuit inside the unit) with shut-off valves up-
stream and downstream of it
•
a paddle flow switch to protect the free cooling circuit
•
water safety valve to protect the free cooling circuit
•
expansion vessel with water pressure gauge to protect
the free cooling circuit
For this version, the intermediate heat exchanger is always
in series with the user-side heat exchanger and therefore
the head losses inside the machine do not change with the
operating mode.
The use of a decoupling exchanger allows only the water
contained in the circuit inside the unit to be glycolated
and to use pure water in the system, thereby obtaining
an immediate economic saving and improving the heat
exchange on individual user points.
OPTIONS
/LN: low noise unit
In the unit with /LN option, the technical compartment
that houses the compressors is fully soundproofed with
sound absorbing material and soundproofing material.
HYDRAULIC MODULES
All units can be fitted with hydraulic module in various
configurations:
•
/1P: hydraulic module with one pump
•
/2P: hydraulic module with two pumps
•
/1PS: hydraulic module with one pump and buffer tank
•
/2PS: hydraulic module with two pumps and buffer tank
All the above-mentioned modules have pumps with stand-
ard discharge head.
Hydraulic modules with one pump have:
•
one pump
•
a gate valve on the delivery side of the pump
•
an expansion vessel
Hydraulic modules with two pumps have:
•
two pumps
•
a check valve on the delivery side of each pump
•
a gate valve on the outlet of the delivery manifold
•
an expansion vessel
In the version with 2 pumps, these are always with one
on standby while the other is working. Switching over be-
tween the pumps is automatic and is done by time (to
balance the hours of operation of each one) or in the event
of failure.
Hydraulic modules with tank also have:
•
a tank with drain valve and air valve