EasyManuals Logo
Home>Lennox>Heat Pump>HP21

Lennox HP21 User Manual

Lennox HP21
53 pages
To Next Page IconTo Next Page
To Next Page IconTo Next Page
To Previous Page IconTo Previous Page
To Previous Page IconTo Previous Page
Page #9 background imageLoading...
Page #9 background image
Page 9
TABLE 3
Compressor Winding
Temperature Sensor
Trip Ohms
Temp. Rise
Reset Ohms
Temp. Fall
TSC−2 Bristol or Copeland
Compressor
25K to 35K 8.4K to 10K
Two-Speed Control Manual Override
The manual override button is designed to be an aid in ser-
vicing and troubleshooting the control or the unit. When the
button is pushed and then released, the control bypasses
the five minute override delay.
Reset
Range
TABLE 4
Resistance Through
Compressor Winding
Temperature Sensor
K-ohms (ohms x 1000)
Voltage Across TSC Ter-
minals S1 and S2 with
Unit Running
DC Volts +.15
0
1.0
5.5
6.9
8.4
10.0
16.0
20.0
24.0
25.0
30.0
35.0
.02
.92
3.4
3.9
4.3
4.7
5.6
6.0
7.0
6.8
6.3
---
Trip
Range
+
DC volts
Measured with unit running.
COMPRESSOR WINDING SENSOR
OPERATING RANGE
Do not use the override button for eleven seconds after
power-up. If the button is pushed during the ten second
power-up delay, the button has no effect. The control com-
pletes the five minute delay.
LED OFF"
MAY MEAN UNIT FAULT" CONDITION
If the unit will not run and the LED is not lit, a unit lockout
condition is indicated. Breaking and remaking thermostat
demand will reset the control. Activate the compressor by
pressing and releasing the override button (see illustra-
tion). If compressor starts, the control is good and should
not be replaced. Proceed through the troubleshooting flow-
chart in the Unit Information Manual to locate the source of
the lockout. If the compressor does not start, a problem
probably exists elsewhere in the unit. Check the unit volt-
age and proceed through the unit troubleshooting
flowchart in the Unit Information Manual.
LED ON"
MEANS TSC FAULT" CONDITION
If the unit will not run and the LED is lit, the TSC may be in
Safety Dormant Lockout (a lockout caused by self-test fail-
ure or high voltage spike).
To determine if the control is in Safety Dormant Lockout,
briefly turn off power at the disconnect. When power is re-
stored, check the LED. If the LED is lit, the control is
damaged and must be replaced. If the LED is not lit, the
control is probably good and should not be replaced until
eliminated by all other checks. Confirm this by activating
the compressor (press and release the override button with
thermostat demand present). If the compressor starts, the
control was in safety dormant lockout (due to high voltage
spike or self-test failure) and the control should not be re-
placed. If the compressor does not start, the control is
probably good and the problem is located elsewhere in the
unit. Proceed through the troubleshooting flowchart to lo-
cate the problem. Start by checking all manually reset
controls (high pressure switch etc...)
Service Instructions:
1− If light comes on and stays lit, turn off power at dis-
connect for at least 3 seconds.
NOTE−Breaking thermostat demand will not reset the
control if the control is in a Safety Dormant Lockout.
2− If LED is on when power is restored, replace TSC.
3− If light goes out see troubleshooting flowchart in
Unit Information Manual.

Table of Contents

Other manuals for Lennox HP21

Questions and Answers:

Question and Answer IconNeed help?

Do you have a question about the Lennox HP21 and is the answer not in the manual?

Lennox HP21 Specifications

General IconGeneral
BrandLennox
ModelHP21
CategoryHeat Pump
LanguageEnglish

Related product manuals