Oil Flow Relay (Flow Indicator)
In-line flow indicator with alarm contact for forced-oil cooling circuits on OFAF/ODAF transformers. The visible dial shows whether oil is actually moving in the pump circuit; the built-in contact raises an alarm or trips standby cooling when flow drops below the set value — protecting the windings before thermal damage develops.
* Models, pipe sizes and flow set-points are confirmed per order against factory datasheets — request the dimensional PDF with your inquiry.
Where It Sits in the Cooling System
Pump outlet monitoring
Mounted in the forced-oil line after the circulating pump — confirms the pump is actually moving oil, not just running.
Cooling supervision
Low-flow contact feeds the cooler control cabinet: standby coolers start, or an alarm is raised at the SCADA.
Retrofit friendly
Send photos of the old relay and the pipe diameter — we match the connection and set-point before quoting.
Frequently Asked
Which flow set-point do we need?
It follows your cooler design (flow rate and pipe size). Tell us the pump circuit data or send the old relay's nameplate — we confirm the set-point with the factory.
Do you also supply the Buchholz relay and valves for the same transformer?
Yes — gas relays, pressure relief valves, level gauges, breathers and butterfly valves are consolidated in one shipment. See the complete accessories kit.
Replacing an oil flow relay?
Send photos of the old unit and the pipe diameter — we match and quote within 24 hours.