T-M50 / T-M50 ASME Service Manual
Ver. 1.05
62
CONFIDENTIAL
12-9. (B) ON/OFF conditions: BTU requirements
A. C
alculating the ON/OFF conditions of the T-M50
【
Condition needed to turn the T-M50 ON
】
(T
set
– T
in
) × GPM × 500 > 11,900
【
Condition needed to turn the T-M50 OFF
】
(T
set
– T
in
) × GPM × 500 < 5,950 or T
in
= T
set
Where: T
set
= Output set temperature and T
in
= Inlet temperature
B. Calculation example
Set temperature: T
set
= 120˚F
Flow rate = 2.5 GPM
【
Condition needed to turn the T-M50 ON
】
(120 – T
in
) × 2.5 × 500 > 14,900 T
in
< 110.5˚F
【
Condition needed to turn the T-M50 OFF
】
(120 - T
in
) × 2.5 × 500 < 11,900 T
in
> 115.2˚F
The outlet temperature at that moment will be 120˚F
C. ON/OFF table
Flow rate (GPM)
Set temperature
(˚F)
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
ON
52.4
76.2
84.1
88.1
90.5
92.1
93.2
94.1
100
OFF
76.2
88.1
92.1
94.1
95.2
96.0
96.6
97.0
ON
67.4
91.2
99.1
103.1
105.5
107.1
108.2
109.1
115
OFF
91.2 103.1 107.1
109.1
110.2
111.0
111.6
112.0
ON
72.4
96.2
104.1
108.1
110.5
112.1
113.2
114.1
120
OFF
96.2 108.1 112.1
114.1
115.2
116.0
116.6
117.0
ON
87.4
111.2 119.1
123.1
125.5
127.1
128.2
129.1
135
OFF
111.2 123.1 127.1
129.1
130.2
131.0
131.6
132.0
ON
97.4
121.2 129.1
133.1
135.5
137.1
138.2
139.1
145
OFF
121.2 133.1 137.1
139.1
140.2
141.0
141.6
142.0
ON
107.4 131.2 139.1
143.1
145.5
147.1
148.2
149.1
155
OFF
131.2 143.1 147.1
149.1
150.2
151.0
151.6
152.0
ON
117.4
141.2
149.1
153.1
155.5
157.1
158.2
159.1
165
OFF
141.2
153.1
157.1
159.1
160.2
161.0
161.6
162.0
ON
137.4 161.2 169.1
173.1
175.5
177.1
178.2
179.1
185
OFF
161.2
173.1 177.1
179.1
180.2
181.0
181.6
182.0
