WSHP-SVX015C-EN
55
Pre-Start
Test Modes
There are three methods in which the “Test” mode can
be cycled at LTB-Test 1 and LTB-Test 2.
1. Step Test Mode - This method initiates the different
components of the unit, one at a time, by
temporarily shorting across the two test terminals
for two to three seconds.
For the initial start-up of the unit, this method
allows the technician to cycle a component “On”
and have up to one hour to complete the check.
2. Resistance Test Mode - This method can be used
for start-up providing a decade box for variable
resistance outputs is available. This method
initiates the different components of the unit, one at
a time, when a specific resistance value is placed
across the two test terminals. The unit will remain
in the specific test mode for approximately one
hour even though the resistance is left on the test
terminals.
3. Auto Test Mode - This method is not recommended
for start-up due to the short timing between
individual component steps. This method initiates
the different components of the unit, one at a time,
when a jumper is installed across the test terminals.
The unit will start the first test step and change to
the next step every 30 seconds. At the end of the
test mode, control of the unit will automatically
revert to the applied “System” control method.
For unit test steps, test modes, and step resistance
values to cycle the various components, refer to the
service test guide for component operation table.
Table 8. Service test guide for component operation
Test Step
Mode
Fan
Econ
Comp 1
Comp 2
Heat 1
Heat 2
Ohms
1
Fan
On
Minimum
Position Off
Setpoint 0%
Off
Off
Off
2.2K
Minimum
Ventilation
On
Selectable
Off
Off
Off
Off
2
Economizer
Test Open
On
Open
Off
Off
Off
Off
3.3K
3
Cool Stage 1
On
Minimum
Position
On
Off
Off
Off
4.7K
4
(a)
Cool Stage 2
On
Minimum
Position
On
On
Off
Off
6.8K
5
Reheat
On
Minimum
On
On
Off
Off
33K
6
Heat Stage 1
On
Minimum
Off
Off
On
Off
10K
7
Heat Stage 2
On
Minimum
Off
Off
On
On
15K
Note:
The exhaust fan will turn on anytime the economizer damper position is equal to or greater than the exhaust fan setpoint.
(a)
Steps for optional accessories and non-applicable modes in unit will be skipped.
Sequence of Operation
ReliaTel
™
™
Controls
Units are offered with the ReliaTel
™
control.
ReliaTel
™
control is a microelectronic control feature,
which provides operating functions that are
significantly different than conventional
electromechanical units. The master module is the
ReliaTel
™
refrigeration module (RTRM).
The RTRM provides compressor anti-short cycle timing
functions through minimum “Off” and “On” timing to
increase reliability, performance and to maximize unit
efficiency.
Upon power initialization, the RTRM performs self-
diagnostic checks to insure that all internal controls are
functioning. It checks the configuration parameters
against the components connected to the system. The
LED located on the RTRM module is turned “On”
within one second after power-up if all internal
operations are okay.
ReliaTel
™
™
Control Cooling without an
Economizer
When the system switch is set to the “Cool” position
and the zone temperature rises above the cooling
setpoint control band, the RTRM energizes the (K9)
relay coil located on the RTRM. When the K9 relay
contacts close, the compressor contactor (CC1) coil is
energized provided the low pressure control (LPC1),
high pressure control (HPC1) and discharge line
thermostat (TDL 1) are closed. When the CC1 contacts
close, compressor (CPR1) start to maintain the zone
