44
VLT
®
3500 HVAC
MG.35.B1.02 – VLT is a registered Danfoss trademark
Load and motor, group 1..
This group of parameters has been reserved for the
adjustments necessary to adapt VLT 3500 HVAC to
the application and motor.
Function:
The adjustment of VLT 3500 HVAC's U/f characteristic
to the load characteristic from centrifugal pumps or
fans.
With the factory setting [10], the AEO function (Auto-
matic Energy Optimizing) is active. This means that
the frequency converter automatically adjusts the volt-
age to the current load from the pump or fan motor,
which ensures optimum efficiency and optimally re-
duced motor noise. The AEO function is active from
20% of f
MAX
(parameter 202).
100 Load (LOAD TYPE)
Value:
Variable torque low (VT MODE-LOW)
[0]
Variable torque medium (VT MODE-MED)
[1]
Variable torque high (VT MODE-HIGH)
[2]
Variable torque low with constant torque start
(VT LOW W/CT)
[3]
Variable torque, medium, with constant torque
start (VT LOW MED W/CT)
[4]
Variable torque, high, with constant torque
start (VT HIGH W/CT)
[5]
No operation (NO OPERATION)
[6]
No operation (NO OPERATION)
[7]
No operation (NO OPERATION)
[8]
Variable torque with AEO function and
constant torque start (ENERGY CT.ST)
[9]
★
Variable torque, low, with AEO (ENERGY VT.L) [10]
Variable torque, medium, with AEO
(ENERGY VT.M)
[11]
Variable torque, high, with AEO
(ENERGY VT.H)
[12]
Area where the AEO- function
will typically be active
1. VT low
2. VT medium
3. VT high
A. Theoretically square torque curve for centrifugal
pumps and fans.
Description of choice:
Variable torque (VT) low
[0],
medium
[1]
or high
[2] is
chosen if the load is square (centrifugal pumps, fans).
The choice of torque characteristic should be made
taking into account the need for trouble-free opera-
tion, minimum energy consumption and the lowest
possible acoustic noise level.
Variable torque (VT)
low
[3],
medium
[4]
or high
[5]
with constant torque
(CT) start
is selected if there is a need for a greater
break-away torque than that obtainable with the
three first-mentioned characteristics.
The curve for constant torque is followed, until the set
reference is reached; from that point onwards the
characteristic chosen for variable torque is followed.
Variable torque with AEO function and constant tor-
que start
[9] is selected if the variable torque charac-
teristic is unknown and there is a need for a high
break-away torque.
Variable torque low
[10],
medium
[11]
and high
[12]
with AEO is selected where, in the start-up situation,
a load characteristic has to be followed which corre-
sponds to variable torque low, medium and high up
to 20% of f
MAX
, parameter 202.
The AEO function is now active; it adjusts the voltage
to the optimum load characteristic, which provides
optimum efficiency and optimally low motor noise.
There is only one AEO-curve available for VLT 3575-
3800 and 3542-3562, 230 V. Even if [10], [11] or [12]
is programmed the device uses the AEO VT LOW
curve.
3.5 Parameter gr
oup 1
NB!:
NB!:
NB!:
NB!:
NB!:
Where parallel motors are to be installed, it is
not advisable to use the AEO function.
