Graco Therm-O-Flow 200 Instructions Manual page 18

Installation Procedure
Check the Resistance Between the Supply
Unit and the True Earth Ground.
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 corrected.
Use a meter that is capable of measuring resis-
tance at this level.
Checking Resistance.
18
Sensor Resistance Checks.
To reduce risk of injury or damage to equipment, con-
duct these electrical checks with the main disconnect
OFF.
The package includes up to eight heat sensors and con-
trollers for each of the heated zones. To check 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 in the RTD Sen-
sors chart below.
Check resistance at ambient room temperature
(63°– 77° Fahrenhei
RTD Sensors
Zone Component
1 Ram Plate
2 Fluid Pump
3 Dispense Hose 1
4 Dispense Gun 1
5 Dispense Hose 2
6 Dispense Gun 2
7 Dispense Hose 3
8 Dispense Gun 3
t).
Terminals Value Range
2011 & 2021 108 +/- 2% ohms
2051 & 2061 108 +/- 2% ohms
2081 & 2091 108 +/- 2% ohms
2111 & 2121 108 +/- 2% ohms
2261 & 2271 108 +/- 2% ohms
2291 & 2301 108 +/- 2% ohms
2321 & 2331 108 +/- 2% ohms
2351 & 2361 108 +/- 2% ohms
311208P