Variable Air Volume Systems - Trane IntelliPak WEHE Series Installation, Operation And Maintenance Manual

Commercial rooftop air handlers with cv, vav, or szvav controls

page of 123

/ 123
Contents
Table of Contents
Bookmarks

Table of Contents

WARNING

Hazardous Voltage!

HIGH VOLTAGE IS PRESENT AT TERMINAL BLOCK 1TB1

OR UNIT DISCONNECT SWITCH 1S14. Disconnect all

electric power, including remote disconnects before

servicing. Follow proper lockout/tagout procedures to

ensure the power can not be inadvertently energized.

Failure to disconnect power before servicing could

result in death or serious injury.

2. Close the disconnect switch or circuit protector switch

that provides the supply power to the unit's terminal

block 1TB1 or the unit mounted disconnect switch

1S14.

3. Turn the 115 volt control circuit switch 1S1 and the 24

volt control circuit switch 1S70 to the "On" position.

4. Open the Human Interface access door, located in the

unit control panel, and press the SERVICE MODE key to

display the first service screen. Refer to the latest

edition of the appropriate SAHF-PTG manual for CV or

VAV applications for the SERVICE TEST screens and

programming instructions.

5. Use

Table 20, p. 75

to program the Supply Fan for

operation by scrolling through the displays.

6. Once the configuration for the Fan is complete, press

the NEXT key until the LCD displays the "Start test in

__Sec." screen. Press the + key to designate the delay

before the test is to start. This service test will begin

after the TEST START key is pressed and the delay

designated in this step has elapsed. Press the ENTER

key to confirm this choice.

WARNING

Rotating Components!

During installation, testing, servicing and

troubleshooting of this product it may be necessary to

work with live and exposed rotating components. Have

a qualified or licensed service individual who has been

properly trained in handling exposed rotating

components, perform these tasks. Failure to follow all

safety precautions could result in rotating components

cutting and slashing technician which could result in

death or serious injury.

7. Press the TEST START key to start the test. Remember

that the delay designated in the previous step must

elapse before the fans will begin to operate.

8. With the system in the SERVICE MODE and the supply

fan rotating in the proper direction, measure the

amperage at the supply fan contactor 1K16 & 1K15. If

the amperage exceeds the motor nameplate value, the

static pressure is less than design and the airflow is too

high. If the amperage is below the motor nameplate

value, static pressure may be too high and cfm may be

too low. To determine the actual cfm (± 5%);

RT-SVX35H-EN

a. Measure the actual fan rpm

b. Calculate the Theoretical bhp

i. Actual Motor Amps X Motor (hp)

Motor Nameplate Amps

c. Plot this data onto the appropriate Fan Performance

Curve in

Figure 42, p. 80

the two points intersect, read straight down to the

cfm line.

Use this data to assist in calculating a new fan drive if the

cfm is not at design specifications.

An alternate method with less accuracy is to measure the

static pressure drop across the evaporator coil. This can be

accomplished by;

a. Drilling a small hole through the unit casing on each

side of the coil.

NOTICE:

Equipment Damage!

Coil damage can occur if care is not taken when drilling

holes in this area.

b. Measure the difference between the pressures at

both locations.

c. Plot this value onto the appropriate pressure drop

curve in

Figure 47, p. 82

data in

Table 22, p. 101

Drops) to assist in calculating a new fan drive if the

cfm is not at design specifications.

d. Plug the holes after the proper cfm has been

established.

9. Press the STOP key at the Human Interface Module in

the unit control panel to stop the fan operation.