QUALITROL® 900/910 RPRR
Rapid pressure rise relays
Protection and detection of
dangerous sudden pressure changes
• 100% factory calibrated and tested to ensure performance
• Multiple mounting and calibration options for gas or oil applications
• From the original creator of mechanical rapid pressure rise relays
Description Patented mechanical device for
detection of sudden pressure events based on the
rate of pressure rise and safe limits established
by transformer manufacturers. When a dangerous
pressure rise has been detected, the QUALITROL
rapid pressure rise relay (RPRR) will change
state. This can be used as an alarm or trip signal
to minimize the potential of transformer
tank damage.
Application For transformer and other
electrical apparatus protection. Can be
used in both oil (QUALITROL 900) or
gas (QUALITROL 910) space of
a transformer.
Product Summary

Protection and detection of

• Devices calibrated to quickly alarm or trip during

dangerous sudden pressure changes rapid pressure rise changes (see response curves below)
• Actuation only occurs based on rate of pressure rise and will not
occur under normal pressure variations caused by temperature
change and vibration
• Can be subjected to full vacuum or 20 PSI positive pressure
without damage
• Standard operation from -40 to 180ºF ( -40 to 82ºC)
• Special units available for operation at -67ºF (-55ºC)
` 100% factory calibrated and • Units are serialized and calibration records are maintained
tested to ensure performance • Factory tested for switch (contact) performance and response time
• Field test kit available for simple GO/NO-GO test to assure proper
functionality of the device
Multiple mounting and calibration • Flange or thread mounting options available for both vertical or
options for gas or oil applications horizontal mounting
• Models calibrated for proper response in gas or oil space applications
(see response curves below)
From the original creator of • Original creator of patented bellows technology for mechanical
mechanical rapid pressure rise relays rapid pressure rise detection
• Over 25 years of experience and refnement in rapid pressure rise
protection with greater than 100,000 units installed
RPRR response curves
900 Series Response Limits 910 Series Response Limits

Seal-in relay (909-300)
• Latching relay to “seal-in�?momentary switch
actuations common with detection of rapid
pressure rise events
• Confgurable for VAC or VDC
• Two output relays
• LED lights to indicate active status and actuation
• Low profle
• Redundant make/break circuit requirement
protects against false trips due to damaged wiring
• UL certifed for use in hazardous locations
(Class 1, Div 2)
Factory test fxture (FIX-601)
• Mimics the calibration and verifcation
testing performed at the factory for all
QUALITROL RPRRs
• Designed for use in repair shops and transformer
manufacturing plants
• Built in LED indicator lamps show test
status and results
Field test kit (KIT-013-1)
• Easy feld test kit for “go/no-go�?testing of
all QUALITROL RPRRs
• Rugged carrying case
• Setup and test instructions in case
• Power supply and other required components
provided in kit