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. Electrical Descripons
1. Power
a. 120 VAC, 50-60 Hz, 3-wire grounded NEMA 5 power cord.
GFCI source required. Note: For 240 VAC, a hardwire
connecon is required. Use only 18AWG stranded copper
wire. The controller’s power supply will automacally
detect the incoming power and will output the same
power to your devices. All output devices (feeders) must
match incoming voltage.
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
10
M820 pH/Dual ORP Controller Owner’s Manual