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CAUTION: To avoid analog spikes, place an MOV suppressor directly
across the contactor coils for all of your high load devices. Next, make
sure all cables used for digital and analog inputs are shielded, twisted pair
wire with the shield connected to ground on the Mission side of the cable
and NOT connected on the far end of the cable (to prevent ground loop
current). Finally, avoid running the Mission analog and digital cable in the
same conduit with 120 VAC cables, especially high current cable. Make
sure to dress the Mission signal cables so they do not run parallel to AC or
high current cabling.
3. Connect digital inputs. Verify that power is still off. Mission’s default input
connections are as follows: Inputs 1, 2, and 3 are pump runtime accumulators;
Input 4 is high wet well, Inputs 5 and 6 are pump 1 fail and pump 2 fail, Input
7 is phase fail and 8 is unassigned. Refer to the wiring diagram on the M110/
M800 cover/door and RTU Installation Form in the packing box. Record input
names on the setup form and the diagram. The inputs are normally open
by default. You may use normally closed contacts on inputs 4 through 8.
However, you must tell Mission Technical Support on the unit set up form or
via the telephone. You MUST use normally open contacts on pump runtime
inputs. Refer to the typical wiring for monitoring a standard trouble relay insert
in the back of this manual.
CAUTION: Digital inputs are dry contacts. This means that wires running
to these inputs must not have any voltage supplied. This is the number
one installation mistake. Do not use a common input wire.
Wire supervision: The main board inputs require the use of a 1000 ohm end-
of-line resistor for each digital input used for alarm/event reporting. These
resistors are connected to and placed in parallel with the monitored relay
contacts and allow the main board circuitry to monitor the integrity of the
connections. See Figure 2 for installation. If you cannot easily install the
resistors at the relay, you can install them across the digital input you are
using for that alarm. By doing that, you will not have line supervision.
Pump Runtime Inputs: Inputs 1, 2 and 3 are pre-programmed at our facility
for pump runtime inputs. If you only use inputs 1 and 2 or you are monitoring
just alarms, inputs 1, 2 and 3 can be set to alarm inputs. Call Mission for