MicroLinks Tech H-CAM Provozní pokyny stáhnout pdf (Strana 115)

TM 11574A-OI

3-21

NOTE

TXV Bulb Clamp is soldered to the suction line.

1. Suction Line 4. TXV Bulb

2. Thumbscrew 5. Foam Insulation

3. TXV Bulb Clamp

Figure 3-8. Thermostatic Expansion Valve Bulb.

(b) Checking Superheat. To check the superheat function of the thermostatic expansion

valve perform the following:

NOTE

Proper superheat measurement should be completed at 0 F (-17.8 C) container box

temperature where possible.

Open the upper right Evaporator Fan Motor (EFM#1) access panel (Figure 2-1) to

expose the expansion valve.

Attach a temperature sensor near the expansion valve bulb and insulate. Make sure

the suction line is clean and that firm contact is made with the sensor.

Connect an accurate gauge to the service port directly upstream of the suction

modulating valve.

Set the temperature set point to 0 F (-17.8 C) and run unit until conditions stabilize.

The readings may cycle from a high to a low reading. Take readings of temperature

and pressure every three to five minutes for a total of 5 or 6 readings.

From the temperature/pressure chart (Table 3-8), determine the saturation

temperature corresponding to the evaporator outlet test pressures at the suction

modulation valve.

Subtract the saturation temperatures determined in step 6 from the temperatures

measured in step 5

. The difference is the superheat of the suction gas. Determine

the average superheat. It should be 8 to 12 F (4.5 to 6.7 C).

1 2 ... 110 111 112 113 114 115 116 117 118 119 120 ... 227 228

Žádné komentáře

MicroLinks Tech H-CAM Provozní pokyny Strana 115