HONEYWELL RP470B (01) PDF Document

The HONEYWELL RP470B (01) is a three-port relay that comes in two configurations, RP470A and RP470B, with the following differences:

RP470A Configuration:

• Transmits the higher of two input signals.

• Selects the higher pressure with a sensitivity of .015 psi (1.03 kPa).

• Is used in sensor lines, such as LP914 or LP915 temperature sensors with a 1.25 to 2.50°F (0.68 to 1.3°C) accuracy, depending on sensor span.

• Has a gray body.

RP470B Configuration:

• Locks out one pressure signal when a second pressure signal is higher.

• Functions as a repeater for signal isolation.

• Functions as a lower-of-two-pressures selector.

• Has a gray and black body.

In a lower-of-two-pressures application, the HONEYWELL RP470B (01) requires a 0.007 Filter Restrictor (part no. 14002913-002) if the input is not already restricted, such as a one-pipe device input.

The HONEYWELL RP470B (01) can either be suspended on tubing or mounted on a surface.

For surface mounting:

1. Use the provided mounting clip.

2. Secure the clip to a wall or panel using a No. 10 x 1/2 in. sheet metal screw (obtain locally).

3. Snap the relay into the mounting clip.

All connections on the HONEYWELL RP470B (01) are sharp barb 5/32 in. (4 mm) O.D. polyethylene tubing connections. To prevent damage to these sharp barb connections, do not attempt to cut or pull the tubing off.

To remove tubing correctly:

1. Cut the tubing a few inches from the control device.

2. Use a coupling to reconnect the tubing.

To check out the HONEYWELL RP470B (01) in this configuration, you must ensure that the higher-of-two-input pressures at Ports 3 and 5 is transmitted through output Port 2.

Testing depends on the application:

• Lockout Relay application: Ensure that the relay passes the signal at Port 2 to Port 3 if the pressure at Port 5 is lower than the pressure at Port 2. When the pressure at Port 5 is greater than the pressure at Port 2, lockout should occur.

• Lower-of-two-pressures application: Make sure that the output is the lower pressure.

Models:

• RP470A Higher-of-Two Pressures Relay

• RP470B Lockout Relay or Repeater

Operating Pressure Range:

• Normal: 0 to 18 psi (0 to 124 kPa)

• Maximum: 30 psi (207 kPa)

Maximum Safe Air Pressure: 30 psi (207 kPa)

Ambient Operating Limits:

• Temperature: 0 to 140°F (-18 to 60°C)

• Relative Humidity: 5 to 95%

Air Handling Capacity: 0.039 scfm at 1 psi (18 ml/s at 7 kPa) differential

Construction: Molded plastic with neoprene diaphragm and valox valve seat

In the RP470A configuration, the relay compares two input pressures at Port 3 and Port 5.

• When the pressure at Port 3 is greater than the pressure at Port 5, Port 3 supplies the output through Port 2, and the output at Port 2 equals the pressure at Port 3.

• When the pressure at Port 5 is greater than the pressure at Port 3, Port 3 closes off, and the output at Port 2 equals the pressure at Port 5.

NOTE: Accuracy decreases when used with circuits having 0.005 restrictors (e.g., TP974, 0.30 psi) compared with those having 0.007 restrictors (0.15 psi).

In the RP470B configuration, the operation is as follows:

• When the pressure at Port 2 is greater than the input pressure at Port 5, Port 2 supplies output through Port 3.

• When the pressure at Port 5 is greater than the pressure at Port 2, the diaphragm closes off the output (Port 3). This action prevents the Port 2 signal from passing through Port 3.

The following table identifies the ports of older Honeywell pneumatic relays when upgrading to a HONEYWELL RP470B (01) in an RP470A configuration.

The following table identifies the ports of older Honeywell pneumatic relays when upgrading to a HONEYWELL RP470B (01) in an RP470B configuration.

When piped as a repeater, the HONEYWELL RP470B (01) provides circuit isolation by repeating the input pressure with a second air source. The signal at Port 5 blocks Port 3 until the signal at Port 2 builds up a matching pressure. This maintains the pressure at Port 3 to be equal to Port 5. Port 3 acts as an exhaust port in this configuration.

For a lowest-of-several-pressures application, multiple HONEYWELL RP470B (01) relays are used. In this setup, each relay acts as a repeater, but they only repeat the lowest input pressure. It is important to note that all inputs must be isolated, and a restricted main is required for this application.