Check The Resistance Between The Supply Unit And The True Earth Ground; Checking Resistance - Graco Therm-O-Flow 243698 Instructions Manual

Check the Resistance Between
the Supply Unit and the True
Earth Ground
WARNING
FIRE, EXPLOSION, AND ELECTRIC
SHOCK HAZARD
To reduce the risk of fire, explosion, or
electric shock the resistance between the
supply unit components and true earth
ground must be less than 0.25 ohms.
Have a qualified electrician check the resistance
between each supply unit component and the true
earth ground. The resistance must be less than
0.25 ohms. If the resistance is greater than 0.25
ohms, a different ground site may be required. Do
not operate the system until the problem is cor-
rected.
NOTE: Use a meter that is capable of measuring
resistance at this level.

Checking Resistance

WARNING
ELECTRIC SHOCK HAZARD
Do not open the electrical control panel,
unless you are a trained professional.
Before opening the control panel, make sure
that all power has been removed from the
control panel.
You can check the resistance of the supply unit's heat
sensors and heaters.
NOTE: Check resistance at ambient room temperature
(63° -77°F).
309213G
Installation
Sensor Resistance Checks
To verify the RTD sensors to be used with the 2- or
4-zone heat control box, refer to the tables below.
RTD Sensors - 2-Zone Control
Zone Component
1 Dispense
Hose 1
2 Dispense
Gun 1
RTD Sensors - 4-Zone Control
Zone Component
1 Dispense
Hose 1
2 Dispense
Gun 1
3 Dispense
Hose 2
4 Dispense
Gun 2
An ohm meter can be used to check the resistance
between the terminals indicated. To check the sensor
resistance:
1. Make sure the power is off and that the disconnect
switch is in the OFF position.
2. Make electrical resistance checks for the compo-
nents.
3. Replace any parts whose resistance readings do not
comply with the ranges listed.
WARNING
ELECTROCUTION HAZARD
To reduce risk of injury or damage to
equipment, conduct these electrical checks
with the main disconnect OFF.
Terminals
1091 & 1101
1161 & 1171
Terminals
1161 & 1171
1231 & 1241
1301 & 1311
1371 & 1381
Installation
Value Range
108 + 2%
ohms
108 + 2%
ohms
Value Range
108 + 2%
ohms
108 + 2%
ohms
108 + 2%
ohms
108 + 2%
ohms
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