Time Control Functions (Not Clock Schedule); Oil Pump Is On/Post Lube (Oil Pump); Ent; Timer - McQuay MicroTech Unit Controller Installation And Maintenance Data

"SET-UP OPTIONS"
This keypad will produce seventeen or eighteen separate
displayed functions (depending on the software version) with
each separate press of the keypad. Each is listed in the
keypad table with the individual options or ranges shown.
The first of these are Reset Options. There are six (6) op-
tions associated with this function. They are:
1. None
2. AMP
3. CHW
If one of these options is to be selected, the statement
"Reset Options= "ZZZ" in this example represents any one
of the 6 options listed. To change the displayed statement,
press "+/Yes", or " -/No" keypad. With the desired option
displayed, press "=/Enter" to establish the option in the
Microprocesor memory. If reset options are chosen, their in-
clusion in the program will be displayed by successive
keypresses of the Setpoints section keys,--"Water Temps"
and/or "Max Amp Limit",
For a detailed explanation of the available "Reset" feature,
see the subsection "Reset Options".
Tower Staging will control cooling tower fan operation; but
only if the control relays required are field installed, and wired
to initiate the operation of one or more tower fans.
Enable Lag, Disable Lag, and Delay Timer "Set-up Op-
tions" are control values that are required only if the unit is
one of two compressors (PF unit), or two units connected in
a "Lead-Lag/Load Balance" configuration.
For a detailed explanation of these three functions, see the
section marked "Lead-Lag/Load Balance':

TIME CONTROL FUNCTIONS (Not Clock Schedule)

Statements such as "Waiting High Amps" or "Waiting -Low
Sump T" are time dependent, but they can not be modified
Table 13. Time Controlled Functions.
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28 403

4. ENT

5. AMP ENT
6. AMP CHW
by an adjustment of the time interval.
To assist the operator, the following provides a summary
of timed functions, whether or not they are adjustable, their
location, and time frame.
A brief description of each listed function follows:
Start-to-Start / Stop-to-Start-These two timers limit the fre-
quency of motor starting to assure longer motor life. Cen-
trifugal compressors unload to 10% and continue to operate
until the water temperature is overcooled by a few degrees.
The combination of compressor capacity reduction and
temperature control are intended to minimize the need for too
frequent starting. If more frequent starting seems to be re-
quired to prevent wide temperature fluctuations, the applica-
tion or equipment and system control should be examined.
Oil Pump is On / Post Lube (Oil Pump)-These two time
functions provide bearing lubrication through time controll-
ed operation of the oil pump both before and after compressor
operation. The time periods alloted are satisfactory for all sizes
of McQuay Centrifugal compressors.
Condenser Pump Timer-This timer determines the length
of time the condenser pump will operate before the main com-
pressor motor control relays (MCR) are energized. Some ex-
tended time may be required; but only if a delay is required
to refill the system, average condenser water temperature, or
prove closure of system flow controls. A long condenser pump
time interval, without the compressor operating is not
desirable. Five to ten seconds is adequate.
An exception to the short time interval exists where one con-
denser pump serves two or more machines. In this case, the
pump might be running for a very long period of time with
the second or third chiller inoperative.
Start-Up Option
Start-Up Option
None (Software)
None (Software)
Start-Up Option
Start-Up Option
Start-Up Option
Start-Up Option
None (Software)
Clock Schedule
Soft Load
None (Software)
20 min. to 60 min.
3 min. to 20 min.
30 sec.
30 sec.
5 sec. to 240 sec.
2 min. to 60 min.
1 min. to 10 min.
15 sec. to 240 sec.
30 sec.
0 to 51 hours
0 to 120 min.
Seconds