180R9288_AQ109686503100en-001301 | 71
© Danfoss | 2023.12
Operation guide
Installation, Operation and Maintenance Manual for PAHT 20-90 pumps
Trouble shooting
fish bone chart
1
. N
o
fl
o
w
/p
re
ssu
re
3
. H
ig
h t
o
rqu
e o
n e
l. m
o
to
r
4
. N
o
is
e f
ro
m p
u
m
p
5
. N
o
is
e
f
ro
m
ins
ta
ll
a
ti
o
n
2
. R
e
du
ce
d fl
o
w
/p
re
ss
u
re
1
.1 D
ry r
u
n
n
in
g
1
.2
P
ump
r
e
v
e
rs
in
g
1
.3 N
o r
o
ta
ti
o
n o
f e
le
c
tr
ic m
o
to
r
1
.4 N
o r
o
ta
ti
o
n o
f p
u
m
p
1
.5 A
x
ia
l f
o
rc
e o
n p
u
m
p s
h
a
ft
1
.6
P
um
p
da
mag
e
2
.1
.5
Pr
e
-t
re
a
tm
e
n
t
2
.1
.6
M
a
in
filt
ra
tio
n
2
.1
W
e
a
r i
n p
u
m
p
(in
te
rnal
l
e
a
k
a
g
e
)
2
.1
.7 T
y
p
e o
f fl
u
id
2
.1
.8
H
ig
h
flui
d
t
e
mp
e
ra
tu
re
4
.1
A
ir
in
flui
d
4
.2
B
le
e
d
ing
c
ond
it
ion
s of
pu
m
p
4
.3
M
in
/m
a
x
n
o
minal
inl
e
t p
res
su
re
4
.4 P
u
m
p r
e
v
e
rs
in
g
4
.5 H
ig
h r
o
ta
ti
o
n s
p
e
e
d (
R
P
M
)
4
.6
O
u
tl
e
t p
res
sure
5
.1
I
n
le
t/
ou
tle
t c
on
ne
c
ti
on
s
(h
o
ses
/p
ip
es
)
5.
2
Le
ngt
h
/d
im
e
n
si
on
s of
inl
e
t/
o
ut
le
t l
in
e
5
.3
Ho
se
st
iffn
e
ss
5.
4
H
o
ses
/p
ip
es
m
o
u
n
te
d
di
re
c
tl
y
o
n
f
ra
m
e
5.
5
V
ib
ra
ti
o
n d
a
m
p
e
r u
n
d
e
r t
h
e
e
le
c
tric
m
o
to
r
3
.1
T
o
o
h
igh
o
u
tl
e
t p
re
ss
ure
from
pu
m
p
3
.3
C
on
st
a
n
t t
orq
u
e
3
.4 W
a
te
r p
u
m
p d
a
m
a
g
e
4
.7 S
o
ft s
ta
rt
/s
to
p
P
U
M
P
F
AI
LE
D
3
.2
P
um
p
s
ta
rt
s aga
in
st
p
re
ss
ure
2
.2
Lo
w
i
n
le
t p
re
ss
ure
2
.3
R
PM
