Milnor System 7 - How Chemwait Works in Milnor Mark I

MSSM0248AE/9526BV (1 of 1)
ÈHOW “CHEMWAIT” WORKS IN
MILNOR MARK I, II, III, IV, AND V MICROPROCESSOR
WASHER-EXTRACTOR CONTROLLERS
“CHEMWAIT” is a feature in the Milnor washer-extractor controller whereby a central chemical injection
system can service several washer-extractors. When the chemical injection system is serving another machine, each
washer-extractor controller can accept a command from the injection system to “stop the timer and do not start the
injection signal.”
An independent output from Milnor to the chemical system declares: “THIS MACHINE DESIRES TO
INJECT ONE OR MORE UNNAMED CHEMICAL(S).” (The same independent output is used regardless of
the chemical(s) that will be subsequently requested.) To cause the Milnor timer to stop and delay the “COM-
MENCE CHEMICAL INJECTION” signals, an independent input from the chemical system to Milnor must
respond, “WAIT” (within two seconds).
In the absence of a “WAIT” response, the Milnor signal(s) start two seconds after the inject request, or two
seconds after the “WAIT” response is extinguished. The duration of the inject signals will be whatever is com-
manded in the washing program.
“WAIT” commands will be ignored unless the machine has desired to inject less than two seconds before.
When several washer-extractors desire chemicals simultaneously, it is the central chemical injection systems’ re-
sponsibility to decide which machine will receive chemicals first. It is also the central chemical injection systems’ respon-
sibility to cope with the situation when one or more washer-extractors simultaneously desire more than one chemical,
although the latter case may be avoided by only commanding one chemical injection at a time—using Milnor’s exclusive
“do not drain” feature to subsequently inject more than one chemical in the same bath.
The “DESIRES TO INJECT” and “WAIT” signals must be via potential-free contacts capable of faithfully
handling 10 MA (.01 amperes) at 5 VDC. The specific “COMMENCE CHEMICAL INJECTON” signals will
be either 120 VAC or 240 VAC, depending on the specific MILNOR model, and via relay contacts capable of
conducting a maximum of 9 VA (i.e., a maximum of either 80 MA (.08 amperes) at 120 VAC or 40 MA (.04
amperes) at 240 VAC).
“CHEMWAIT” is presently available in all Mark I, II, III, IV, and V controllers, but does require the optional
#2 output board. Ask factory for more information.
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