Adjusting the Reset Span | Trane VAV-SVX02B-EN specification

Model 3011—Pneumatic

Volume Regulator

Use the following procedure to set-up the PVR:

1.Select damper action (NO or NC). Loosen damper selection switch screw and align to either the NO or NC pointer with damper pointer and tighten screw.

2.Now determine the type of thermostat that will be used. If a direct-acting thermostat is used, the reset start pressure is typically 8 psi. If a reverse-acting thermostat is used, the reset start pressure is typically 3 psi (see Figure 11).

3.With an accurate gage (0-10 psi) connected to port “G”, regulate the thermostat pressure to port “T” to desired start point pressure.

4.Adjust reset start to indicate 0 psi on port “G” and continuing adjusting to indicate a pressure slightly higher than 0 psi, (i.e., 0.1 psi).

Figure 11–Adjusting Reset Start

Adjust to obtain 0±0.1 psi at port G

			CN	I
			NO	N CR
			NO
	psi	M	DAMPER
	psi		DAMPER
0	10		G
			G

Connect 0±10 psi Gage

Factory-set at 5 psi

Adjustable (0±10 psi)

Connect Hand Pump

Input desired LO stat pressure at t-stat port

0±20 psi

RESET START Handpump

LO STAT ΔP

HI STAT ΔP

RESET SPAN

NOTE: The arrows on the damper selector must be aligned exactly or the range of the controller will be limited .0 psi

Adjusting the Reset Span (3011)

The reset span is factory-set at 5 psi.This is the thermostat pressure difference from which the PVR delivers flow from minimum to maximum setpoints.This range is not normally changed unless a special control scheme is used where control operation must be changed.

To field adjust a different reset span, follow these steps:

1.Connect an accurate gage to port “G”.

2.Apply 20 psi to port “T”.

3.Adjust reset span to indicate the desired span on port “G” (see Figure 12).

4.LO-stat and HI-stat delta P must now be readjusted (see following calibration procedure)