Pentair IntelliFlo VS+ SVRS Blockage Alarm
The IntelliFlo VS+ SVRS pump includes a Safety Vacuum Release System (SVRS) that complies with the ASME/ANSI A112.19.17-2002 standard, which defines how quickly the pump must stop when a suction blockage event occurs. Understanding how SVRS works and how auto-restart behaves is critical for safe operation.
How SVRS Works
The system setup for SVRS requires that the suction vacuum level be adjusted to 25 inches of mercury (Hg) or less at the pump strainer housing connection.
When something blocks the suction or the pump fully dead-heads, the pump shuts off immediately (within 1 second). The pump also shuts off after a few seconds of dead heading with the same alert. The "Blocked system" alarm on the control panel indicates a blocked suction line. This alarm resets automatically after two (2) minutes and the pump restarts.
The operator must ensure that all suction and return fittings are clean and unobstructed whenever the pump is started.
SVRS Auto Restart Behavior
The SVRS Auto Restart setting controls what happens after a blockage event. The default setting is Enabled with a 2-minute restart time.
When SVRS Auto Restart is enabled, after an SVRS alarm the pump will attempt to soft prime after the amount of time set in the SVRS Restart Time. During the soft prime, the pump starts at the Minimum RPM setting and slowly ramps up to the desired speed setting. If the pump senses a blockage again, it shuts off and repeats the soft prime. The pump attempts this soft prime sequence ten (10) times before attempting a full prime. During the full prime attempt, the SVRS is off and a blockage would go undetected.
If SVRS Auto Restart is set to "Disabled," the pump will not automatically restart after a blockage alarm. The pump must be manually restarted by pressing the Reset button and then the Start/Stop button. Note: Disabling the Auto Restart setting does not disable the SVRS suction blockage detection feature itself.
The SVRS Auto Restart time can be set from 30 seconds to 5 minutes, or to "Manual Restart." Check local codes and ordinances before changing this setting.
SVRS Auto Restart Settings
| Setting | Default | Range |
|---|---|---|
| SVRS Auto Restart | Enabled | Enabled / Disabled |
| SVRS Restart Time | 2 minutes | 30 seconds–5 minutes, or Manual Restart |
False SVRS Alarms
The IntelliFlo SVRS can be sensitive to air in the circulation system, which can cause a false SVRS alarm — a blockage alarm when no actual blockage is present. It is always recommended to bleed the air from the filter when starting the pump. Suction-side air leaks in the system can contribute to false SVRS alarms.
The Ramp Speed setting (default 200 RPM) is also available to help minimize false SVRS tripping when the pump switches between speeds. Using the 400 RPM ramp setting may cause false tripping of the SVRS function when switching speeds.
Check Valves and Hydrostatic Valves
Testing the SVRS
The SVRS function should be tested on all new installations. The operation can be verified using one of two methods described in the manual:
- Valve method: The system must have a fast-closing ball, butterfly, or sliding gate valve in the suction line. Close this valve quickly in less than one (1) second. The pump should shut off immediately.
- Test mat method: Use a test mat to quickly cover the suction outlet to simulate an entrapment event. The pump should shut off immediately.
This pump complies with the ASME/ANSI A112.19.17-2002 SVRS standard. Note that this pump may not protect individuals from hair entrapment, limb entrapment, or evisceration.