Grundfos CU 321 User Manual

25
Surroundings
Note: For outdoor installation, the CU 321 must be installed in a minimum NEMA 3R enclosure with provisions
for heating and ventilating designed to keep the CU 321 within its operating temperature limits.
Safeguards
• The CU 321 is protected against short-circuits on
motor terminals U, V, W.
• Monitoring of the intermediate circuit voltage
ensures that the CU 321 cuts out if the intermedi-
ate circuit voltage is too low or too high.
• The CU 321 is protected against ground fault on
motor terminals U, V, W.
7. Pressure sensor voltage chart
Voltage to pressure chart for the CU 321 pressure sensor. Measure DC voltage between "terminal 12" and
"terminal 60", see fig. 18. "Err 2" will appear in the CU 321 display if the signal is outside the range or if the
signal is reversed.
8. Disposal
This product or parts of it must be disposed of in an
environmentally sound way:
1. Use the public or private waste collection service.
2. If this is not possible, contact the nearest
Grundfos company or service workshop.
CU 321
3 hp, 1- and 3-phase
5 hp, 3-phase
5 hp, 1-phase
Enclosure (CU 321 unit) NEMA 0 NEMA 1
Enclosure with fitted NEMA 1 kit NEMA 1 –
Max. relative air humidity 93%
Ambient temperature Max. 113°F
Min. ambient temperature
during full-scale operation
32°F
Temperature during
storage/transport
Min. –13°F
Max. 160°F
DC voltage psi DC voltage psi DC voltage psi
22.5 0.0 to 1.3
20.9 40.4 to 41.7 19.3 80.8 to 82.1
22.4 2.5 to 3.8
20.8 42.9 to 44.2 19.2 83.4 to 84.6
22.3 5.1 to 6.3
20.7 45.5 to 46.7 19.1 85.9 to 87.2
22.2 7.6 to 8.8
20.6 48.0 to 49.3 19.0 88.4 to 89.7
22.1 10.1 to 11.4
20.5 50.5 to 51.8 18.9 90.9 to 92.2
22.0 12.6 to 13.9
20.4 53.1 to 54.3 18.8 93.5 to 94.7
21.9 15.2 to 16.4
20.3 55.6 to 56.8 18.7 96.0 to 97.3
21.8 17.7 to 18.9
20.2 58.1 to 59.4 18.6 98.5 to 99.8
21.7 20.2 to 21.5
20.1 60.6 to 61.9 18.5 101.1 to 102.3
21.6 22.7 to 24.0
20.0 63.2 to 64.4 18.4 103.6 to 104.8
21.5 25.3 to 26.5
19.9 65.7 to 66.9 18.3 106.1 to 107.4
21.4 27.8 to 29.1
19.8 68.2 to 69.5 18.2 108.6 to 109.9
21.3 30.3 to 31.6
19.7 70.7 to 72.0 18.1 111.2 to 112.4
21.2 32.8 to 34.1
19.6 73.3 to 74.5 18.0 113.7 to 114.9
21.1 35.4 to 36.6
19.5 75.8 to 77.1 17.9 116.2 to 117.5
21.0 37.9 to 39.2
19.4 78.3 to 79.6 17.8 118.7 to 120.0
Subject to alterations.

Grundfos CU 321 Specifications

General

Brand	Grundfos
Model	CU 321
Category	Control Unit
Language	English