Grundfos CU 301 - Constant-Pressure Control System; System Description; System Functionality

5
1.3 System sizing
To ensure the correct function of the system, it is
important that the pump is of the right type.
During operation, the CU 301 controls the pump
speed within the range from 3,000 min
-1
to 10,700
min
-1
, see fig. 6.
It is recommended to follow the guidelines below:
Fig. 6
The following must be fulfilled:
1. Min. head at no flow < static head + system pres-
sure.
2. Max. head at max. flow > dynamic head + system
pressure.
Max. head at max. flow and min. head at no flow can
be found in the following table:
TM01 8547 0400
H [m]
Q [m³/h]
Max. head at max. flow
Min. head at no flow
Pump curve
at 10,700 min
-1
Pump curve
at 3,000 min
-1
Q
max
Pump type
Min. head
at Q = 0 m³/h,
3,000 min
-1
Max. head
at Q = Q
max
,
10,700 min
-1
[m] / [feet] [m] / [feet]
SQE 1 - 35 18 / 59 29 / 86
SQE 1 - 50 28 / 91 44 / 131
SQE 1 - 65 37 / 121 59 / 177
SQE 1 - 80 46 / 151 75 / 222
SQE 1 - 95 56 / 184 90 / 270
SQE 1 - 110 65 / 213 105 / 315
SQE 1 - 125 74 / 243 120 / 360
SQE 1 - 140 81 / 266 136 / 405
SQE 1 - 155 92 / 302 151 / 450
SQE 2 - 35 19 / 62 35 / 105
SQE 2 - 55 29 / 95 54 / 164
SQE 2 - 70 38 / 125 71 / 215
SQE 2 - 85 47 / 154 88 / 267
SQE 2 - 100 56 / 184 108 / 328
SQE 2 - 115 66 / 217 128 / 390
SQE 3 - 30 15 / 49 26 / 75
SQE 3 - 40 24 / 79 42 / 123
SQE 3 - 55 31 / 102 56 / 164
SQE 3 - 65 39 / 128 70 / 205
SQE 3 - 80 47 / 154 84 / 246
SQE 3 - 95 55 / 180 98 / 287
SQE 3 - 105 62 / 203 113 / 328
SQE 5 - 15 7.7 / 25 11 / 36
SQE 5 - 25 15 / 49 23 / 77
SQE 5 - 35 23 / 75 36 / 117
SQE 5 - 50 30 / 98 48 / 159
SQE 5 - 60 38 / 125 61 / 200
SQE 5 - 70 45 / 148 73 / 240
SQE 7 - 15 8.6 / 28 9 / 33
SQE 7 - 30 18 / 59 23 / 82
SQE 7 - 40 27 / 89 37 / 126