34
SSA-SVX06H-EN
Parameter 6-15 in the VFD = 60Hz
Supply Fan Maximum Speed Setpoint = 80%
Effective Supply Fan Maximum VFD Output = 80% x
60Hz =48Hz
If the desired maximum operating point from the
catalog fan table is lower than 40Hz, parameter 6-15 on
the VFD must be reprogrammed to 50 Hz. The VFD is
preset from the factory to a default of 25 Hz for the
lower limit and does not need to be reprogrammed.
S
Su
up
pp
plly
y F
Fa
an
n M
Miin
niim
mu
um
m S
Sp
pe
ee
ed
d S
Se
ettp
po
oiin
ntt ((R
Ra
an
ng
ge
e:: 0
0--
1
10
00
0%
%,, D
De
effa
au
ulltt:: 0
0%
%))
The Supply Fan Minimum Speed Setpoint correlates to
the minimum reference setting in the VFD (25Hz from
the factory). With the Supply Fan Minimum Speed
Setpoint at its default value of 0%, and parameter 6-14
in the VFD at its default value of 25hz, the minimum
VFD output will be 25Hz. If the user chooses to increase
the supply Fan Minimum Speed Setpoint, it will
effectively increase the minimum VFD output from its
configured value, up to the Effective Supply Fan
Maximum VFD Output as determined by the Supply
Fan Maximum Speed Setpoint. See the example below:
E
Ex
xa
am
mp
plle
e::
Parameter 6-14 in the VFD = 25Hz
Effective Supply Fan Maximum VFD Output (based on
Supply Fan Maximum Speed Setpoint) = 60Hz
Supply Fan Minimum Speed Setpoint = 50%
Effective Supply Fan Minimum VFD Output =
(Effective Supply Fan Maximum VFD Output – VFD
Parameter 6-14) x 50% + 25Hz = 42.5Hz
Table 8. Maximum fan speed setpoints and effective supply fan maximum VFD output
When VFD Parameter 6-15 = 60Hz
When VFD Parameter 6-15 = 50Hz
Supply Fan
Maximum
Speed
Setpoint
Effective
Supply Fan
Maximum
VFD Output
(Hz)
Supply Fan
Maximum
Speed
Setpoint
Effective
Supply Fan
Maximum
VFD Output
(Hz)
Supply Fan
Maximum
Speed
Setpoint
Effective
Supply Fan
Maximum
VFD Output
(Hz)
Supply Fan
Maximum
Speed
Setpoint
Effective
Supply Fan
Maximum
VFD Output
(Hz)
100%
60
83%
49.8
100%
50
83%
41.5
99%
59.4
82%
49.2
99%
49.5
82%
41
98%
58.8
81%
48.6
98%
49
81%
40.5
97%
58.2
80%
48
97%
48.5
80%
40
96%
57.6
79%
47.4
96%
48
79%
39.5
95%
57
78%
46.8
95%
47.5
78%
39
94%
56.4
77%
46.2
94%
47
77%
38.5
93%
55.8
76%
45.6
93%
46.5
76%
38
92%
55.2
75%
45
92%
46
75%
37.5
91%
54.6
74%
44.4
91%
45.5
74%
37
90%
54
73%
43.8
90%
45
73%
36.5
89%
53.4
72%
43.2
89%
44.5
72%
36
88%
52.8
71%
42.6
88%
44
71%
35.5
87%
52.2
70%
42
87%
43.5
70%
35
86%
51.6
69%
41.4
86%
43
69%
34.5
85%
51
68%
40.8
85%
42.5
68%
34
84%
50.4
67%
40.2
84%
42
67%
33.5
S
Stta
arrttu
up
p