ZENITH 140
INSTRUCTION MANUAL
100
The decision on whether or not to attempt to start the failed pump on
subsequent pump cycles will be determined by
P300 Max. Attempts
. Once
the number of attempts stipulated have been made the pump will be put
out of service until such time the Device Fail input is cleared by a
Reset
(
P391 = 4)
on Digital Input 7. Alternatively, the
+/-
key can be used as a as
a Hot Key, which when pressed, whilst the unit is in RUN, will give details of
any
Device Fail
and provides prompts to
Reset
any failures to the
no fault
condition.
Duty
When this function is selected, the digital inputs are used to determine, via
an ‘auto/manual’ switch,
which one of the devices, connected to the relay
outputs of the Zenith, will be the “lead” or “duty” device.
Consider the example of an application using 2 pumps. Each pump is
connected and controlled by one of the Zenith relay outputs, the pump duty
and setpoints have been programmed as detailed in
Using the Relays
,
earlier in this chapter. The signals providing details on the “lead” or “duty”
pump ‘status’ are co
nnected to the digital inputs as described in
Chapter 2
Installation
, and the input
Type
P372, 375, 378, 381, 384, 387, 390 is
configured as detailed in
Input Type
, earlier in this chapter.
Pump 1
is connected and programmed to operate on
Relay 1
Pump 2
is connected and programmed to operate on
Relay 2
Pump 1 Duty
signal is connected to
Digital Input 3
Pump 2 Duty
signal is connected to
Digital Input 4
The type of switch to be used to determine the duty is selected and
configured as detailed in
P301 Switch Mode
.
Standard Switch Mode (P301
=
0
Standard)
When a standard rotary type switch is used, to determine auto/manual duty
one input per device is required, with each input being assigned to the
appropriate device relay output that it relates to, this is determined by
Assignment P374, 377, 380, 383, 386, 389, 392.
In the case of our
example
Digital Input 3
will be assigned to
Relay 1 (P380 = 1)
and
Digital
Input 4
will be assigned to
Relay 2 (P383 = 2)
.