Check Resistance - Graco Therm-O-Flow 20 EasyKey NXT 2200 Instructions-Parts List Manual

Installation

Check Resistance

Check the Resistance Between the Supply
Unit and the True Earth Ground
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.
Sensor Resistance Checks
Conduct these electrical checks with the main discon-
nect OFF.
The package includes a heat sensor and controller for
each of the six heated zones. To check sensor resis-
tance:
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 Table 2.
Check resistance at ambient room temperature
(63°– 77°F [17°– 25°C]
14
).
Table 2: RTD Sensor Resistance
Zone Component
1 Platen
2 Fluid Pump
3 Dispense Hose 1
4 Dispense Gun 1
5 Dispense Hose 2
6 Dispense Gun 2
Heater Resistance Checks
Conduct these electrical checks with the main power
disconnect OFF.
To check heater 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. Refer to Electrical Schematics on page 54
for wiring diagram information.
3. Replace any parts whose resistance readings do
not comply with the ranges listed in Table 3 on page
15.
Check resistance at ambient room temperature
°F [
(63°– 77 17°– 25
Terminals Range (ohms)
2011 & 2012 108 +/- 2%
2051 & 2061 108 +/- 2%
2081 & 2091 108 +/- 2%
2111 & 2121 108 +/- 2%
2261 & 2271 108 +/- 2%
2291 & 2301 108 +/- 2%
°C]).
311976A