15
JOHNSON CONTROLS
FORM 155.21-W2 (1209)
DOWNLOADING HISTORIES TO A LAPTOP FROM
AN OPTIVIEW CONTROL CENTER
Refer to details explained in FORM 155.21-O1.
10. Lead selector and cycling control to provide similar lead
selection and cycling of lag units for three (3) units is
available: Kit No. 366-44684D in NEMA I enclosure.
Consult your YORK/Johnson Controls representative.
11. Sequence control kits (see
Fig
's 12, 13 and Note 10)
assume a constant chilled water flow and a constant
leaving chilled water temperature to sense the cooling
load. Sequence control kits are not designed for variable
chilled water flow or with reset of the leaving chilled
water temperature (see Fig
s. 18 to 20 and Note 2).
12. Maximum allowable current draw between circuits for
field installed devices is 2 amp holding and 10 amps
inrush (see OptiView™ Control Center Wiring Diagram
Form 155.21-W1).
13. For required field wiring connections of the chilled water
pump contacts (terminals 44 and 45 on OptiView™
Control Center field wiring terminal block TB2) and
chilled water flow switch (terminals 1 and 12 on
OptiView™ Control Center field wiring terminal board
(see Wiring Diagram Form 155.21-W1).
The chilled water flow switch is a safety control. It must
be connected to prevent operation of the chiller whenever
chilled water flow is stopped. The use of the chilled water
flow switch for purposes other than protection of the
chiller may be accomplished in several ways. Two flow
switches, a flow switch and a relay or separate contacts
on the same flow switch.
15. Do not apply voltage on field wiring terminal blocks
TB4 and TB6 in YORK OptiView™ Control Center, as
115VAC source is fed from terminals 1 and 2 .
16. Entering and Leaving Chilled and Condenser Water Tem
‑
perature Sensors are supplied by YORK as a standard
item on all YiA units.
1. This drawing shows recommended field control wiring
modifications (by others) to the standard OptiView™ Con
‑
trol Center Wiring Diagram. For additional single stage
YIA OptiView wiring details see Form 155.21-W1.
2. If more than one of these modifications is to be utilized
with a particular unit, additional consideration must be
given to the application to insure proper functioning
of the control system. Consult your YORK/Johnson
Controls representative.
3. The additional controls and wiring for these modifica
‑
tions are to be furnished and installed in the field (by
others) (see Warnings on page 2).
4. The controls specified are recommended for use, but
other controls of equal specifications are acceptable.
5. All wiring shall be in accordance with the National Elec
‑
trical Code, and applicable State and Local Codes.
6. Each 115VAC field connected inductive load, i.e. relay
coil, motor starter coil, etc., shall have a transient sup‑
pressor wired (by others) in parallel with its coil, physi
‑
cally located at the coil. Spare transient suppressors are
furnished in a bag in the OptiView™ Control Center.
7. The OptiView™ Control Center is factory furnished
for Manual Restart After Power Failure as a standard
function. The control center can be field changed from
Manual restart to Auto restart after a power failure, For
details consult a qualified YORK/Johnson Controls
service technician.
8. Two (2) unit controls schemes are suitable for 8° – 12°F
water range. Constant chilled water flow is assumed at
all loads. For other requirements contact your YORK/
Johnson Controls representative.
NOTES
