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 3
Operation,
Continued
When S port pressure drops more than 1 psig (6.9 kPa) below R port pressure, the
internal relief valve opens to vent the R port signal to prevent it from being locked up.
Figure 1. Analog Relay.
Figure 2. Ratio Relay 1 In = 2 Out.
OPERATIONAL FORMULA:
TD + T – R
Since TR is zero, and TD = T
then 2T = R
Ratio Relay 1 In = 2 Out
Output pressure is equal to two times the input pressure. Output cannot exceed the air
supply pressure.
Input Output
T & TD R (psig)
(psig)
0 0
2 4
8 16
12 24
R cannot be greater than S
Discontinued