Install Instructions

RM7898A 7800 SERIES VALVE PROVING PRIMARY RELAY MODULES
11 66-1161—04
Typical Valve Proving System
Function
Valve Proving consists of monitoring the pressure in the space
between two shutoff valves, MV1 (upstream) and MV2
(downstream). The Valve Proving function, identified by letters
A through F, operates as follows:
The tolerance on all Valve Proving timing values is ±10%.
The following are steps performed during Valve Proving tests.
This section is for background information and does not define
the exact behavioral requirements.
As the RM7898 starts Purging:
a. MV2 is commanded to be open while MV1 remains
closed; to depressurize the space. After 4 seconds,
MV2 is commanded closed again.
b. This is followed by a three second delay during which
the Valve Proving pressure switch (VPS) is ignored.
c. Thereafter, the VPS is monitored for the duration of the
Valve Proving test time and, if it turns on, then a lock-
out occurs. (Because the gas pressure has increased
due to a leaky upstream valve.) (Low pressure test)
d. MV1 is commanded to be open while MV2 remains
closed, to pressurize the space. After 4 seconds,
MV1 is commanded closed again.
e. This is followed by a three second delay, during
which the Valve Proving pressure switch (VPS) is
ignored.
f. Thereafter, the VPS is monitored for the duration of
the Valve Proving test time and, if it turns off, then a
lockout occurs. (Because the gas pressure has
decreased due to a leaky downstream valve.) (High
pressure test.)
Pressure Switches for Valve Proving
System
The Valve Proving System requires a pressure switch to be
installed to monitor the pressure in the internal space between
the two shutoff valves. Recommended pressure switches are
the following Honeywell non-manual reset models:
Table 7. Honeywell Pressure Switch Selection for Valve Proving System.
Pressure Switch Selection
1. Determine the maximum operating inlet pressure for the
upstream valve; for example, 5.0 psi (140 in. wc).
2. Divide the inlet pressure by two (2.5 psi [70 in. wc], for
example).
3. From column 2 in Table 7 find the operating range upper
limit that is closest to but greater than the inlet pressure
divided by two. In the example given, the possible selec-
tions from column 1 are the C6097A1129 and
C6097A1137 with an operating range upper limit of 7 psi.
(The C6097A1079 and C6097A1087 with an upper limit
of 60 in. wc are close, but 60 in. wc is less than the 70 in.
wc minimum, so the next higher range must be selected.)
4. From column 6, select the preferred mounting type, 1/4
in. NPT or Flange. For example, if a flange mount is
required, the pressure switch choice from column 1
would be the C6097A1137.
Pressure Switch Installation and
Adjustment
1. Refer to the instructions for theC6097A Pressure
Switch, form number 65-0237.
2. Install the C6097A Pressure Switch according to the
instructions.
3. Adjust the setpoint to 50% of the maximum operating
inlet pressure for the upstream valve.
4. Complete the operation and checkout procedures in the
instructions.
123456
Model Number
Operating
Pressure Range
Maximum
Differential
(Additive)
Maximum
Continuous Rated
Pressure (psi)
Switch Action at
Setpoint Mounting Type
C6097A1004 0.4 to 5 in. wc 0.24 in. wc 2.9 Breaks N.O. to C
connection on
pressure fall.
1/4 in. NPT
C6097A1053 3 to 21 in. wc 0.48 in. wc 5.0
C6097A1061 Flange
C6097A1079 12 to 60 in. wc 2.4 in. wc 1/4 in. NPT
C6097A1087 Flange
C6097A1129 1.5 to 7 psi 0.3 psi 9.3 1/4 in. NPT
C6097A1137 Flange
C6097A1210 0.4 to 4 in. wc 0.24 in. wc 2.9