Johnson Controls yzh Fascicule

Johnson Controls Unitary Products

035-22286-001-A-0909

GENERAL INFORMATION

The YorkGuard VI Demand Defrost control as a replacement
part for prior versions of the YorkGuard control.

NOTE:  For direct replacement of YorkGuard VI, replace the
control only.

Service replacement kit consists of:

• YorkGuard “VI” Defrost Control.

CONTROL CONFIGURATION FOR

ALL APPLICATIONS

Most jumper settings should be set to match jumpers on board
being removed.

Remove control from packaging and configure the control as
follows:

1.

Specify the desired Low Temperature Cut Out (LTCO)
using the jumper on the control.

2.

Specify the desired Balance Point (BP) using the jumper on
the control.

3.

Specify appropriate defrost curve using the jumper on the
control. See Table 1.

4.

Verify that the Y2 LOCK jumper is set. This jumper is not
applicable to a single stage compressor system.

5.

Specify if the Heat Pump is installed with a fossil fuel fur-
nace using the FFUEL jumper. The jumper should be ON
for a fossil fuel furnace installation and OFF for an air han-
dler installation.

6.

Specify Switch Point jumper using the jumper on the con-

trol.

7.

Verify that the HOT HEAT PUMP is set appropriately.

8.

Specify compressor delay using jumper on the control.
“ON” will shut-off compressor when entering and leaving
defrost.

FIGURE 1: Demand Defrost Control Module

TABLE 1: Defrost Initiate Curves

YZB/HC3B/HL3B 2 & 2.5 Ton 4 & 5 Ton 3 & 3.5 Ton 1.5 Ton

YZE/HC5B/HL5B

2 Ton

4 & 5 Ton

3 Ton

N/A

YZE03811

N/A

N/A

3 Ton

N/A