M920 & M920W pH/Dual ORP Controller Owner’s Manual
i. External audible/visible alarm (oponal)
j. pH sensor - BNC connecon
k. ORP sensor - BNC connecon
l. Oponal dry contact ORP1 output (contact factory for
instrucons)
F.ElectricalDescripons
1. Power
a. 120 VAC, 50-60 Hz, 3-wire grounded NEMA 5 power cord. GFCI
source required. Note:TFor240VAC,ahardwireconneconis
required.Useonly18AWGstrandedcopperwire.Thecon-
troller’spowersupplywillautomacallydetecttheincoming
power and will output the same power to your devices. All
outputdevices(feeders)mustmatchincomingvoltage.
2. Dip Switches (1-4)
1: pH/ORP interlock (default: OFF)
• No ORP1 or ORP2 feed if pH is feeding (ON).
2: pH/ORP alert interlock (default: ON)
• No ORP1 or ORP2 feed if pH is in alert mode (ON).
• No interlock (OFF)
3: Acid/Base default acid (default: OFF)
• Feed base chemical when pH level falls below set point. (ON)
• Feed acid chemical when pH above set point. (OFF)
4: Not in use.
Figure 3: Dipswitches
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