Suction Conditions; Electrical Connection - Grundfos CRK Series Installation And Operating Instructions Manual

D1
D2
D3
Fig. 10 Vertical installation
Pump mounting flange dimensions:
Pump
Frame D1 D2
type
MTR 1s, 1, 5.51 6.30
NEMA
[140] [160]
3, 5
MTR 10, 15, 7.87 8.86
NEMA
[200] [225]
20
7.48 8.66
MTR 32 NEMA
[190] [220]
9.45 10.43
MTR 45, 64 NEMA
[240] [265]
5.51 6.30
CRK 2, 4 NEMA
[140] [160]
5.51 6.30
SPK 1, 2, 4, 8 NEMA
[140] [160]
5.51 6.30
CRK 2, 4 IEC
[140] [160]
3.94 4.53
SPK 1, 2, 4 IEC
[100] [115]
5.51 6.30
SPK 8 IEC
[140] [160]

7.2 Suction conditions

The bottom of the pump strainer must be at least 1 in [22 mm]
above the bottom of the tank.
The pumps are designed to provide full performance down to a
level of A above the bottom of the strainer.
At a liquid level between A and B above the bottom of the
strainer, the built-in priming screw will protect the pump against
dry running.
Note: MTR 32, 45 and 64 pumps have no priming screw.
Pump type A in. [mm]
MTR 1s, 1, 3, 5,
CRK 2, 4, and
SPK 1, 2, 4, 8
MTR 10, 15, 20
MTR 32, 45, 64
6
4 x X
C
D3 L C X
7.09 3.94 ø0.37
1.25" NPT
[180] [100] [9.5]
9.84 4.92 ø0.35
2" NPT
[250] [125] [9]
9.84 5.91 ø0.47
2.5" ANSI
[250] [150] [12]
11.42 6.50 ø0.47
3.0" ANSI
[290] [165] [12]
7.09 3.94 ø0.37
1.25" NPT
[180] [100] [9.5]
7.09 3.94 ø0.37
1.25" NPT
[180] [100] [9.5]
7.09 3.94 ø0.30
1.25" BSPT
[180] [100] [7.5]
5.12 2.52 ø0.30
0.75" BSPT
[130] [64] [7.5]
7.09 3.94 ø0.30
1.25" BSPT
[180] [100] [7.5]
B in. [mm]
1.6 [41] 1.1 [28]
2.0 [51] 1.0 [25]
2.8 [71] –
Fig. 11 MTR 1s, 1, 3, 5, CRK 2, 4, and SPK 1, 2, 4, 8
Fig. 12 MTR 10, 15, 20
Fig. 13 MTR 32, 45, 64
Each pump inlet is protected by a strainer to prevent larger
particles from entering and damaging the pump. If the pumped
liquid contains solid particles larger than the size of the holes in
the strainer, the passage of the strainer may be blocked. In such
situations the performance will drop as a result of a reduced flow
through the pump.
Note: If the suction strainer is removed from the retainer, solid
particles may enter the pump and cause a seizure or even
damage the pump.
In grinding applications Grundfos recommends that the pumped
liquid is screened for abrasive particles before entering the pump.
When pumped, abrasive particles reduce the life of the pump
components. Wear of the pump components caused by abrasive
particles starts when the concentration exceeds 20 ppm.
The table below describes the size of the passage in the strainer.
Pump type
MTR(E) 1s to 3
MTR (E) 5 to 64
CRK and SPK

8. Electrical connection

The electrical connection should be carried out by an authorized
electrician in accordance with local regulations.
Strainer passage
ø in. [mm]
0.08" [2]
0.16" [4]
0.12" [3]