The Walchem WDP420-1NNN controller is now obsolete and has been replaced by the WDP420-1NNU controller which now has integrated USB datalogging and software upgrade capability. Otherwise, both the WDP420-1NNN and the WDP420-1NNU have the same specifications with w/ 2 pulse proportional and 2 on/off control outputs and diagnostic alarm relay, 120 VAC, pre-wired with 6” pigtails (if on/off) or with 10’ cables for e-class pumps (if pulse), no 4-20 mA output, no electrode.
Please click here to view and/or purchase the new replacement controller and to view literature.