Johnson Controls York VCH 20A, Technical Information

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11
Model
Nominal charge
R-410A
(Kg.)
Number of
circuits
Gas line dia-
meter
Liquid line dia-
meter
Additional char-
ge, grs.
(per metre)
L
Maximum length
in straight
sections of inter-
connecting
pipes (m)
L
E
Maximum equi-
valent length
unit interconnec-
ting pipes
(m)
VCH 20A/VIR 25A 8.5 1 1 1/8" (28.5 mm) 1/2" (12.7 mm) 112 50 * 60
VCH 25A/VIR 25A 8.5 1 1 1/8" (28.5 mm) 1/2" (12.7 mm) 112 50 * 60
VCH 30A/VIR 40A 12 1 1 1/8" (28.5 mm) 5/8" (15.87 mm) 170 50 60
VCH 40A/VIR 40A 12 1 1 1/8" (28.5 mm) 5/8" (15.87 mm) 170 50 60
VCH 45A/VIR 45A 9.5 x 2 2 1 1/8" (28.5 mm) 1/2" (12.7 mm) 112 50 60
VCH 60A/VIR 60A 10.5 x 2 2 1 1/8" (28.5 mm) 5/8" (15.87 mm) 170 50 60
VCH 75A/VIR 75A 15 x 2 2 1 3/8" (35 mm) 7/8" (22 mm) 333 50 60
VCH 90A/VIR 90A 16 x 2 2 1 3/8" (35 mm) 7/8" (22 mm) 333 50 60
Ext. pipe diameter Elbow (short radius) 90° bend (long radius)
3/8" 0.3 0.2
1/2" 0.4 0.3
5/8" 0.5 0.4
3/4" 0.5 0.4
7/8" 0.6 0.5
1 - 1/8" 0.7 0.6
1 - 3/8" 1 0.7
1 - 5/8" 1.2 0.8
Example:
L= 2 + 3 + 3 + 6 + 4 + 7 + 6 + = 31
31 < therefore, 50% is correct
To calculate the equivalent length of the interconnecting pipes we use,
just as we would for the pressure drop, the data of one of the liquid
lines; that is to say 1/2" outer diameter. As we see in the diagram, there
4 elbows with an equivalent length of 0.5 m. (as per table) and 2 bends
of 0.4 (as per table). Therefore, to make sure that the pipe equivalent
length is not over the admissible maximum, we have:
L
E
= 2 + 3 + 6 + 4 + 7 + 6 + 4 (0.5) + 2 (0.4) = 22.8 m.
33.8 < therefore, 60 % is correct
Refrigerant charge and pipe diameters
* Starting from a total of 20 m. in length of straight sections (horizontal and vertical) of interconnecting pipes between units, a minimum 7-litre suction
accumulator should be installed in the gas line (of larger diameter).
Maximum length (L):
This is the sum of the lengths of all
horizontal and vertical straight sections in one single direc-
tion (liquid or gas).
Maximum equivalent length (L
E
):
This is the sum of the
lengths of all straight sections of the interconnecting pipes
(liquid or gas) in one single direction, plus the equivalent
length of the accessories (basically elbows and bends). The
equivalent length due to elbows and bends can be seen in
the following table:
Accessory equivalent lengths in meters
Note: The elbows and 45° bends (used in siphons, for example) have half
the equivalent length of the 90° bends.
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