Unit installation

31
5285 873 - 02
Vitocrossal 300, CT3 Series Installation
Appendix
Technical Data (continued)
*3
Boiler has two return connections - the heating return with the lower temperature should be connected to the boiler
return BR1.
*4
Values for calculating the size of the flue system based on 10% CO
2
for natural gas. Flue gas temperatures
measured as gross values at 68º F (20º C) combustion air temperature. The details for partial load refer to an output
of 30% of rated input. Calculate the flue gas mass flow rate accordingly when the partial load differs from that
stated above (subject to the burner mode).
 For information regarding other Viessmann System Technology componentry, please reference documentation
of respective product.
B
oil
e
r Mod
e
l
C
T3
-
17
22
28
37
48
57
72
89
W
e
igh
t
b
o
ile
r
shell
lbs
(kg
)
10
12
(
45
9)
1114
(
505
)
1
2
0
2
(
545
)
16
71
(
758
)
1
75
9
(
7
9
8
)
199
5
(9
05
)
27
06
(
1230
)
30
14
(
1370
)
O
verall wei
g
ht
c
omp
l
ete w
i
t
h
i
nsu
l
. an
d
contro
l
(w/o
b
urner
)
lbs
(kg)
1
22
8
(
557
)
13
52
(
613
)
1455
(
660
)
196
2
(
8
9
0
)
2
06
4
(9
36
)
2
3
22
(
1053
)
30
14
(
1370
)
33
44
(
1520
)
B
oil
e
r wat
e
r
c
ont
e
nt
USG
(L)
71.
3
(
270
)
7
8
.2
(
2
9
8
)
8
7.2
(
330
)
1
2
9
.5
(
4
9
0
)
1
4
0
.
8
(
533
)
1
5
0
.
6
(
570
)
199
.2
(
754
)
221.
9
(
840
)
H
eat exchan
g
er sur
f
ace
w
at
e
r-coo
led
f
t
.
2
(m
2
)
89
.
3
(
8.3
)
106
.
6
(9
.
9)
1
27.
0
(
11.8
)
16
2.5
(
15.1
)
18
4.1
(
17.1
)
22
0
.7
(
20.5
)
30
5.7
(
28.4
)
3
72.5
(
34.6
)
M
ax. operat
i
n
g
temperatur
e
f
t
.
2
(m
2
)
21
0
(99)
M
ax. operat
i
n
g
pressur
e
p
s
ig
k
pa
30
(
207
)
F
lue
g
as resistanc
e
“
w.c
.
P
a
0
.4
0
(
100
)
0
.5
6
(
140
)
0
.
6
4
(
160
)
0
.
80
(
200
)
0
.
88
(
220
)
1
.
08
(
270
)
1
.2
0
(
300
)
1
.
3
2
(
330
)
B
oil
e
r
c
onn
ec
tion
s
boiler supply (B
S
)
&
return (BR1
)
i
n.
(
mm
)
2
b
(
65
)
2
b
(
65
)
3
(
80
)
4
(
100
)
4
(
100
)
4
(
100
)
5
(
125
)
5
(
125
)
Boiler return (BR2
)
*3
i
n.
(
mm
)
2
(
50
)
2
(
50
)
2
(
50
)
3
(
75
)
3
(
75
)
3
(
75
)
4
(
100
)
4
(
100
)
S
afety supply
i
n.
(
mm
)
1
a
(
32
)
1
a
(
32
)
2
(
51
)
2
(
50
)
2
(
50
)
2
(
50
)
2
b
(
65
)
2
b
(
65
)
Bo
ile
r
d
ra
i
n
C
on
de
n
s
at
e
d
rain
i
n.
(
mm
)
1
(
b
)
1
(
b
)
1
(
b
)
1
(
b
)
1
(
b
)
1
(
b
)
1
(
b
)
1
(
b
)
V
ent p
i
p
e
i
nt
e
rnal
Ø
i
n.
(
mm
)
8
(
201)
8
(
201
)
8
(
201
)
10
(
251
)
10
(
251
)
10
(
251
)
1
2
(
301
)
1
2
(
301
)
F
lue
g
as value
s
*
4
T
emperature
(
at a return
t
emperature of 86° F (30°
C)
- at rate
d
i
npu
t
°
F
(
°
C)
1
1
3
(
45
)
1
1
3
(
45
)
1
1
3
(
45
)
1
1
3
(
45
)
1
1
3
(
45
)
1
1
3
(
45
)
1
1
3
(
45
)
1
1
3
(
45
)
- at part
i
a
l
l
oa
d
°
F
(
°
C)
10
4
(
40
)
10
4
(
40
)
10
4
(
40
)
10
4
(
40
)
10
4
(
40
)
10
4
(
40
)
10
4
(
40
)
10
4
(
40
)
T
emperature
(
at a return
t
emperature of 140° F (60°
C)
°
F
(
°
C)
16
7
(
75
)
16
7
(
75
)
16
7
(
75
)
16
7
(
75
)
16
7
(
75
)
16
7
(
75
)
16
7
(
75
)
16
7
(
75
)
Mass
f
low rate (o
f
f
lue
g
as
)
lb
s
/h
(kg
/
h)
7
0
4
(
320
)
9
2
8
(
422
)
1
17
9
(
536
)
1
5
3
1
(
6
9
6
)
1903
(
865
)
2
380
(
1082
)
2
9
7
9
(
1354
)
3
7
0
5
(
1684
)
G
a
s
volum
e
of com
b
u
s
tion
ch
am
b
er an
d
h
eat exc
h
an
g
e
r
f
t
.
3
(m
3
)
8
.
83
(
0.250
)
9
.
9
2
(
0.281
)
1
2.
00
(
0.340
)
1
5.
90
(
0.450
)
18
.4
0
(
0.521
)
21.54
(
0.610
)
4
0
.
6
1
(
1.150
)
42.7
3
(
1.210
)
P
r
e
ss
u
r
e
at
b
oil
e
r
f
l
ue
o
u
tl
e
t
- at part
i
a
l
i
npu
t
P
a

0
-
3

0
-
5

0

0

0

0
- at max
i
mum
i
npu
t
P
a
(
-3
)
(
-4
)
-2

0

0

0

0

0