York YPAL 051 User Manual

JOHNSON CONTROLS

FORM 100.50-NOM6 (1207)

There are two (2) economizer outside air intake hoods 
pro vid ed with the unit. The front and rear hoods are 
made operational per the following instructions:

 •  Remove the screws holding the economizer hood 

ship ping covers in place. Discard covers.

 •  Apply a bead of RTV sealer along the edge of 

both hoods and each pivot joint to prevent water 
leakage.

 •  Rotate the hoods out (each hood is hinged). 

Secure the hoods with screws along the top and 
sides.

 •  Seal any unused screw holes with RTV or by 

re plac ing  the  screw.

The hoods must be installed per the above instructions. 
The dampers may be adjusted by loosening the thumb 
screw, turning the le ver to the desired position, and 
retightening the thumb screw.

No hoods are required for the exhaust air outlet.

Figure 2-8 shows the fi eld wiring to the Simplicity 
control board.  All fi eld control wiring is fi eld supplied 
and installed.

A thermostat (4 stage cool and 3 stage heat) can be used 
on CV and VAV units.  On CV units the thermostat is 
the primary means of control for the unit.  The three 
thermostat heating inputs connect to the P2 terminal 
block on the Simplicity control board to terminals W1, 
W2, and W3.  The four thermostat cooling inputs connect 
to the P2 and P3 terminal block on the Simplicity control 
board to terminals Y1, Y2, Y3, and Y4.

The thermostat should be mounted on an inside wall 
approximately 56” above the fl oor where it will not be 
subject to drafts, sun exposure or heat from electrical 
fi xtures or appliances.

Note that 24 VAC terminal (R) on terminal block P1 
of the Simplicity control board must be used as the 24 
VAC source for the input to the thermostat.  Use of any 
power source external to the controller will result in 
damage to the Unit Controller.

By closing a contact between terminal (R) and (G) on 
terminal block P1 on the Simplicity control board the 
supply fan can be turned on.  This function is typically 
used on CV units and is included with most room 
thermostats.

Note that 24 VAC terminal (R) on terminal block P1 
of the Simplicity control board must be used as the 24 
VAC source for the input to (G).  Use of any power 
source external to the controller will result in damage 
to the Unit Controller.

A space sensor can be used in lieu of a thermostat as 
the primary means of control on a CV unit.  The space 
sensor is connected to terminals (ST) and (GND) of 
terminal block P8 on the Simplicity control board.

A space sensor with a 20,000 potentiometer can be 
used to reset the space temperature set point.  The 
space temperature reset is connected to terminals (SSO) 
and (GND) of terminal P8 on the Simplicity control 
board.

When mounting a space sensor, it should be located on 
an inside wall approximately 56” above the fl oor where 
it will not be subject to drafts, sun exposure, or heat 
from electrical fi xtures or appliances.