Publicidad
Idiomas disponibles
Idiomas disponibles
2.7.5. SFS ACCESSORY - SOFT STARTER
The SFS accessory is used to reduce the start-up current peak, thereby achieving a soft and gradual start, with a noticeable benefit in terms of mechani-
cal wear of the electric motor.
Below is a qualitative drawing to represent a unit with 2 compressors equipped with and without SFS accessory. The inrush current values with the SFS
accessory are indicated in tables "A" Technical data.
Inrush current - without SFS
Inrush
Sp
C [A] Current
Time
T [s]
Inrush current - with SFS
Inrush
Sp
C [A] Current
Time
T [s]
2.7.6. LKD AND LKDP ACCESSORY - LEAK DETECTOR
The LKD accessory allows the detection of refrigerant gas leaks in the technical compartment.
The LKDP accessory (including the LKD accessory) allows the detection of gas leaks throughout the refrigeration circuit.
If a refrigerant leak is detected, two different options are available:
1. Management of a voltage-free contact (for the user):
o CONTACT OPEN -> Alarm triggered
o CONTACT CLOSED -> No alarm triggered
2. Management, in addition to the free contact, of a predefined logic that performs the following actions:
o generation of an ALARM
o unit shutdown with manual reset
2.7.7. VPF - VARIABLE PRIMARY FLOW
The energy used for the cooling unit to work is an important component in the system costs, and reducing the unit consumption, especially with partial
load, is sometimes compromised by the pump unit operating constantly. The higher the absorption of the pumps used to maintain the proper flow of water
in the pipes the more this effect is noticed. A solution that compensates for the problem of the energy absorbed by the pump units is using pumps driven
by inverter technology, able to modulate the flow rate G and reduce power consumption. This is how the systems with constant primary flow and second-
ary decoupled variable flow exist.
The introduction of the VPF system simplifies the systems, using a single primary variable flow circuit, in which inverter controlled pumps are installed as
the only pumps in the system; this solution generates complications related to the calibration, sizing of the venting section and system setting, which bur-
den the client and indirectly could affect the reliability of the machine. The solution proposed by HITECSA combines the simplification of the VPF system,
the reliability of the system solution with primary-secondary variable flow circuits and the additional energy and cost savings derived from managing the
pri- mary with variable flow where energy saving depends on the variation in flow rate ΔPa=f(ΔG)3.
The water content in the primary circuit is very important as it stabilises system operation, the water temperature to the system and the reliability of the
cooling unit in time (minimum suggested content of 5 Lt/kw). The cooling unit will be equipped with primary side pumps with inverter control (managed by
HITECSA) and with system side pumps with inverter control separated by a hydraulic disconnector. The system side pumps will be controlled by the
user or by HITECSA (only one pump).
In addition to significant energy savings, the solution with VPF technology by HITECSA also allows the design of the system's hydraulic circuit to be
simpli- fied and the operating costs to be decreased.
The HITECSA solution offered for variable flow systems is innovative for several reasons:
Stable flow rate modulation required by the system with guaranteed reliability for the chiller installed (even with system flow rate oscillation). The flow
rate can be modulated up to 20% by using pumps with an EC-type of motor.
Simplified system calibration operations.
Design simplification of the solutions to apply to the terminals (balancing the number of 3-way and 2-way valves with due sizing of the venting section).
Maximising the efficiency of the cooling unit in each operating condition for the flow rate to be modulated on the system side following the route of the
load, as well as on the primary side, thereby minimising the pumping energy required for it to operate correctly.
Possibility of simplified and reliable management of multiple units in parallel (avoiding known issues of flowrate variations in traditional VPF systems
when cooling units are switched on/off).
IOM_EQRU-SS_EQRHU-SS_2160a4350_208676_230601_ES-EN-FR-DE-IT
91
EQRU-EQRUSS
EQRHU-EQRHUSS
Publicidad
