York YK-EP B Operation & Maintenance Manual page 203

FORM 160.87-OM1
ISSUE DATE: 8/24/2018
A Program card for a particular chiller type can be used
to re-program other chillers of the same type. For ex-
ample, it is not necessary to have more than one YK-
EP Program card. A single YK-EP card can be carried
to different locations to re-program other YK-EP Op-
tiView™ Control Centers.
A Write Protect Switch on the edge of the Program
card prevents inadvertent writing to the Card during
program downloading.
Handling precautions for the Program card include:
• Do not allow dirt or water to enter the connector
• Operating temperature range for Commercial
grade SD cards is -25°C to 85°C (-13°F to 185°F)
A label on the Program card contains the version and
JCI part number. The version is an alphanumeric code
that identifies the chiller model applicability, language
package, language revision level and chiller control re-
vision level. The version is as follows:
Z.OPT . nn.nn .nnn
Language Package revision level
(00,01,etc)
Language Package (0=English
only, 1=NEMA, 2=CE, 3=NEMA/
CE)
Controls Revision Level (00, 01,
02, etc)
Chiller Model (01=YKEP)
OptiView™ Control Center
Commercial Chiller
Program Download Connector J26
The SD Program card is inserted into connector J26 to
download a program. Refer to instructions under Ser-
vice Replacement.
FeRAM
The FeRAM (Ferroelectric Ramdom Access Memory)
preserves the stored data during power failures. All of
the programmed Setpoints, Sales Order Data and His-
tory Data is stored here. This memory does not require
a battery.
JOHNSON CONTROLS
Real Time Clock
The RTC (Real Time Clock) uses a common CR2032
button-cell lithium battery to maintain the time and
date during power outages. The battery life is over 10
years. This type of battery is used in watches and is
readily available at drug stores and appliance stores.
SMARC Module
The SMARC Module is the processor card for the 031-
03630-007 microboard. The SMARC Module and the
baseboard are assembled as a pair in the board manu-
facturing factory and can not be swapped in the field.
SMARC (Smart Mobility ARChitecture) is a relatively
new standard to enable multiple vendors to provide
high performance embedded processor cards. This
will allow using future processors if the current ones
become obsolete without having to re-design the mi-
croboard.
Watchdog Circuit
The Watchdog circuit performs two functions as fol-
lows:
• Power failure detection
• Program latch-up detection/prevention
The Watchdog Circuit monitors the +5VDC from the
power supply and the +3.3VDC from the onboard reg-
ulator to determine when a power failure is occurring.
If the +5VDC decreases to the threshold of (+4.44VDC
to +4.68VDC) or the +3.3VDC decreases to the thresh-
old of (+2.84VDC to +3.04VDC), a reset is issued to
the microprocessor and the chiller shuts down. When
power is restored, the white screen is displayed and the
boot-up is performed as described above. When the
graphic screen is displayed, the message CONTROL
PANEL – POWER FAILURE is displayed.
The Watchdog Circuit also assures that the entire pro-
gram is being executed and that the program has not
latched-up, bypassing important safety checks. The
Watchdog circuit is a timer that times-out if not given
a reset pulse within its time-out period (1 to 1.204
seconds).
SECTION 5 - SERVICE
5
203