Sequence Of Operation; Compressor Operation; Cooling Operation Errors - York ZF210 Instruction Manual

Sequence of Operation

NOTE: For more in-depth sequence of operation of the
Simplicity® SE control please refer to LIT-12011950 on
www.upgnet.com under Product Center \ Equipment
Catalog \ Commercial Products \ Zoning Systems and
Controls.

Compressor Operation

This section assumes Free Cooling is not available.
a. Compressors are controlled by the Y1 through Y2
thermostat inputs. If the Lead/Lag function is turned OFF,
a Y1 input energizes the C1 output. Thermostat Input
into Y2 energize the C2 output respectively.
b. The FAN output for indoor fan operation energizes with
any cooling output after the Fan On Delay for Cool
expires.
c. CN-FAN output engerizes when either C1 or C2 is
energized.
d. A 30 second interstage delay occurs when multiple
stages are requested. When the thermostat cooling
inputs are lost and the minimum runtime expires, the
compressor outputs stage off.
NOTE: A Y2 input without a Y1 input energizes C1 first and
then C2 30 seconds later.
Continuous Blower
By setting the room thermostat fan switch to "ON," the supply
air blower will operate continuously.
Intermittent Blower
With the room thermostat fan switch set to "AUTO" and the
system switch set to either the "AUTO" or "HEAT" settings, the
blower is energized whenever a cooling or heating operation is
requested. The blower is energized after any specified delay
associated with the operation.
When energized, the indoor blower has a minimum run time of
30 seconds. Additionally, the indoor blower has a delay of 10
seconds between operations.
Optional VAV Startup and Control
If the unit is operated with the manual bypass switch in
the LINE (BYPASS) position and there are VAV boxes
present in the duct system, then boxes must be driven to
the full-open position using a customer-supplied power
source to prevent over-pressurizing and possible
damage to the ductwork.
For units with VFD and VAV control, the unit must first be put
into the Occupied Mode to start operation. The default setting
for all VAV units is 'Unoccupied', therefore the installer must
Johnson Controls Unitary Products
add a jumper wire between terminals R - OCC on the VAV add-
on board to put the unit into 'Occupied' Mode. Additionally, the
unit can be switched between Unoccupied/Occupied mode
through network communications with Si m p l i c i t y
other BAS control systems.
Once placed into the Occupied Mode, the speed of the indoor
blower motor is controlled by duct static pressure. The Duct
Static set point (default = 1.5") is the pressure that the VFD
drive will maintain when operating the unit in VAV mode. If the
duct static pressure reaches or exceeds the high-limit set-point
(default = 4.5"), then the supply fan motor will be shutdown.
The Supply Air Temperature (SAT) is controlled by staging
compressors on and off to satisfy the "Operating Cooling
Supply Air Temp Set point". There are 3 set points that
determine the resulting "Operating Cooling Supply Air Temp
Set point".
1. VAV Cooling Supply Air Temp Upper Set point
(default 60° F)
2. VAV Cooling Supply Air Temp Lower Set point
(default 55° F)
3. VAV Supply Air Temp Reset Set point (default 72° F)
When the Return Air Temp (RAT) is above the "VAV Supply Air
Temp Reset Set point" the SAT will be maintained at +/- 5
degrees of the "VAV Cooling Supply Air Temp Lower Set point".
When the Return Air Temp (RAT) is below the "VAV Supply Air
Temp Reset Set point" the SAT will be maintained at +/- 5
degrees of the "VAV Cooling Supply Air Temp Upper Set point".
When the Outdoor air condition is sufficient for free cooling, the
economizer will modulate to control the SAT to +/- 1 degrees of
the operational set point.
The following components are needed to access the control
points in the Si m p l i c i t y ® SE control. Installation and operation
guides are located on www.upgnet.com under Product Center \
Equipment Catalog \ Commercial Products \ Zoning Systems
and Controls.
1. Local LCD on Unit Control Board.
2. Mobile Access Portal (MAP) Gateway (Portable).
• Source 1 P/N S1-JC-MAP1810-OP
3. MAP Gateway Quick Start Guide P/N 24-10737-16
4. MAP Gateway Instruction P/N 24-10737-8

Cooling Operation Errors

Each cooling system is monitored for operation outside of the
intended parameters. Errors are handled as described below. All
system errors override minimum run times for compressors.
High-Pressure Limit Switch
During cooling operation, if a high-pressure limit switch opens,
the UCB will de-energize the associated compressor, initiate
the ASCD (Anti-short cycle delay), and, if the other compressor
1088917-YIM-B-1014
™ PC and
49