Data Sheet for Product

RL 243 A Commercial Duty Analog Relay Technical Instructions
Document Number 155-107P25
Rev. 1, April, 2000
Siemens Building Technologies, Inc.
Page 7
Figure 9. Minimum Pressure Relay with
Characterized Output.
OPERATIONAL FORMULA:
TD + (T – TR) = R
Since TR = R, then
TD + T = R If TR <
T TD = R if Tr > T
2
If TD = 5 psig, then R cannot be greater than S, and
T – TR cannot be less than 0 psig.
Operation,
Continued
Minimum Pressure
Relay with
Characterized Output
Output pressure is equal to minimum pressure input TD, until input T exceeds TD. Then
output pressure equals one-half of TD plus T.
Figure 10. Characterized Minimum
Pressure Relay.
OPERATIONAL FORMULA:
TD + (T – TR) = R
TR = R, and T –TR cannot be less than zero.
R cannot be greater than S.
Characterized Minimum
Pressure Relay
Output increases rapidly from one-half to minimum pressure setting. Then the output
pressure increases directly with input pressure.
Input Min Output
T (psig) Pressure TR & R
TD (psig) (psig)
0 5 5
5 5 5
10 5 7.5
25 5 15
Min Input Output
Pressure TD (psig) TR & R
T (psig) (psig)
8 0 4
8 4 6
8 8 8
8 16 16
8 25 25
Discontinued