Johnson Controls York YD Manual page 38

Table 6: Warning messages
Message
Warning – Surge
Protection – Excess
Surge Limit
Warning – Setpoint
Override
Warning – Condenser –
High Pressure Limit
Warning – Evaporator –
Low Pressure Limit
Warning – Motor Bearing
Lube Suggested
38
Description
This warning applies to single compressor operation only and only if the Surge
Protection Extended Run setpoint is enabled. The chiller is operating in a Surge
Protection Extended Run period because the Surge Window Count has exceeded
the Count Limit setpoint during single compressor operation. When the Surge Window
Count exceeds the Count Limit setpoint, a 10 minute extended run period is initiated.
During this period, the pre-rotation vanes are driven closed. At the end of the 10 minute
period, if the Surge Window Count is less than the Count Limit, this message is cleared
and vanes are allowed to load. Otherwise, another 10 minute extended run period is
initiated.
A blank BRAM battery-backed memory device (IC location U52 on Microboard) or a failure of
this device was detected during the initialization process that occurs when power is applied
to the control center. Due to this failure, any or all of the programmed setpoints could have
been corrupted. Therefore, all setpoints have been automatically changed to their default
values. All setpoints will have to be programmed to their required values. This message will
clear when the Warning Reset key is pressed in operator (or higher) access level.
The condenser pressure exceeds the High Pressure Warning setpoint threshold,
programmed by a service technician logged in at service access level. While this condition
is in effect, the pre-rotation vanes are inhibited from further opening. This message
automatically clears and the vanes are permitted to open when the condenser pressure
decreases to 5 psig below the setpoint.
The evaporator pressure has decreased to the warning threshold. This threshold is fixed in
water cooling applications. In brine cooling applications, the threshold is a fixed amount
above the programmable safety shutdown threshold. The safety threshold in brine
applications is determined by the brine solution and is determined by the YORK factory.
While this condition is in effect, the pre-rotation vanes are inhibited from further opening.
Warning threshold (psig)
Water
R-134a 27.0
This message automatically clears and the vanes are permitted to open when the evaporator
pressure increases to the reset value.
The operating hours since last motor lubrication has exceeded 1000 hours (the greater
of either Motor #1 Operating Hours or Motor #2 Operating Hours is used for this
calculation). This warning will be displayed until manually cleared by the operator or the
Operating Hours Since Last Motor Lubrication exceed 1200 hours, whereupon
it is replaced by the message Warning – Motor Bearing Lube Required below. The
operator clears this message by entering his/her initials, name or user ID in operator access
level (or higher) using the Motor Lube Acknowledge key on the Motor lubrication screen.
See the for entry instructions. This entry implies both motors were lubricated. The date and
time of this entry is automatically logged as the Date of Last Motor Lubrication and
Time of Last Motor Lubrication. It also resets the Operating Hours Since Last
Lubrication to zero. The date this warning occurs is stored as the Date of Last Motor
Lubrication Warning or Fault. This warning message will only be displayed if the Auto
lube setpoint on the Motor lubrication screen is disabled.
Brine
+2.0 >Safety setpoint
Model YD Mod D with OptiView Control Center
Reset threshold (psig)
Water Brine
28.0 +3.0>Safety setpoint