IOM SyScroll 140 360 Air EVO 361549

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8 - Technical Data (continued)
8.4.1 Variable flow hydronic systems
• Manual flow control
1. Application
2. Description
3. Operation
Provide the user with the required flow rate and hydraulic
balance without the need of mechanical balancing
valve but taking advantage of the energy consumption
optimization of the pump using the frequency drive.
SYSCROLL 140-360 AIR EVO is equipped with hydraulic
module driven by frequency drive that does not provide
continuous modulation of the pump speed but a fixed
water flow rate during commissioning.
The pump motor speed limits must be set during the chiller
commissioning and in accordance with below rules:
- Pump speed high limit should be referenced to the
Nominal Water Flow Rate
- Pump speed low limit should be referenced to the
Minimum Water Flow Rate
IMAGE 01: Frequency vs Speed behavior
[Hand On] enables control of the frequency converter
via the LCP. [Hand On] also starts the motor and allows
entering the required motor frequency with the navigation
keys [▲]/ [▼].
IMAGE 02: LCP DISPLAY
Note: When VPF works at 30 Hz, the absorbed power
consumption of the pump is reduced by 80% compared
to 50Hz pump operation.
• Variable primary flow (Constant ΔP)
1. Application
This option is recommendable on installations with two-
way valves on the customer water loop. This method
ensures that each branch of the water loop has a uniform
water supply without unnecessary energy consumption.
2. Description
For this option, the unit is equipped with a hydraulic
module driven by frequency drive. The modulation of the
pump speed ensures that the Differential Pressure (DP)
remains constant within the system. At minimum partial
loads, the minimum flow across the chiller evaporator
should be ensured or a by-pass valve should be installed
to prevent the evaporator from low flow, which otherwise
is very critical to the chiller system.
IMAGE 03: Constant ∆P Control diagram
Note: In two-pump configuration, there is an alternation of
the pump operation for every 12 hrs.
Note: For the electrical connection of differential pressure
transducer, pressure transducers and By-pass valve, refer
electrical drawings of the hydraulic module.
3. Operation
Delta pressure is measured by 1 pressure sensor. The
modulation control logic PI of the pump speed starts as
soon as pump is in operation in accordance with DP set
point fixed on VFD controller. If the load decreases, the
control valves are closed and that increases the Delta
P, then the speed of the pump is decreased in order to
decrease the Delta P until the setpoint. (Decreasing the
speed to the half, decreases consumption by 90%).
Parameter set 4-XX
Parameter 4-14:
50 HZ (Default)
Parameter 4-12:
30 HZ (Default)