T-K3 Service Manual
Ver. 1.05
53
CONFIDENTIAL
12-10. Pump control ON/OFF conditions: BTU requirements for Intermittent mode
A. Calculating the pump’s ON/OFF condition
【
Condition needed to turn the pump ON
】
( T
set
– T
in
) × GPM × 500 > 18,600
【
Condition needed to turn the pump OFF
】
4 minutes after activation, if the computer detects a BTU requirement of less than 18,600
BTU/h, the computer w ill stop the pump in 90 seconds.
( T
set
– T
in
) × GPM × 500 < 18,600 or
T
in
= T
set
Where: T
set
= Output set temperature and T
in
= Inlet temperature
B. Calculation example
Set temperature: T
set
= 122
˚
F
Flow rate = 2.5 GPM
【
Condition needed to turn the pump ON
】
( 122 – T
in
) × 2.5 × 500 > 18,600 T
in
< 107.1
˚
F
【
Condition needed to turn the pump OFF
】
( 122 – T
in
) × 2.5 × 500 < 18,600 T
in
> 107.1
˚
F
C. ON/OFF table (ON values are the same as OFF values)
Flow rate of pump (GPM)
Set temperature
(
˚
F)
1.0
1.5
2.0
2.5
3.0
3.5
4.0
113
75.8
88.2
94.4
98.1
100.6
102.4
103.7
122
84.8
97.2
103.4
107.1
109.6
111.4
112.7
131
93.8
106.2
112.4
116.1
118.6
120.4
121.7
140
102.8
115.2
121.4
125.1
127.6
129.4
130.7
158
120.8
133.2
139.4
143.1
145.6
147.4
148.7
167
129.8
142.2
148.4
152.1
154.6
156.4
157.7
185
147.8
160.2
166.4
170.1
172.6
174.4
175.7
