York XT AHU - ELECTRIC HEATER AIR FLOW REQUIREMENTS AND START-UP

JOHNSON CONTROLS
48
FORM 102.20-OM2
ISSUE DATE: 6/01/2015
SECTION 2 - START-UP AND OPERATION
Calculate KW per square foot of duct area as: (see step 12)
heater namplate KW
duct area (Sq.Ft.)
FIGURE 37 - MINIMUM AIR VELOCITY REQUIRED FOR SAFE OPERATION
100
2
200 300 400 500 600 700 800 900 1000 1100 1200
4
6
8
10
12
14
16
0
0
100
2
200 300 400 500 600 700 800 900 1000 1100 1200
4
6
8
10
12
14
16
18
22
24
26
28
30
32
20
0
0
KW PER SQ. FT. DUCT AREA
MINIMUM AIR VELOCITY REQUIRED
(FEET PER MINUTE)
KW PER SQ. FT. DUCT AREA
MINIMUM AIR VELOCITY REQUIRED
(FEET PER MINUTE)
FINNED
TUBULAR
CONSTRUCTION
91 - 100° Inlet Air
81 - 90° Inlet Air
Below 80° Inlet A
ir
OPEN COIL
CONSTRUCTION
Starting The Electric Heater
Rotating parts and electrical shock haz-
ards exist. Use the latest lock out/tag out
procedure to the fan motor(s) and heat
power disconnects before servicing. Fail-
ure to follow proper safety precautions
may result in serious injury or death.
Use the following instructions to start up the electrical
heater.
1. Check all electrical connections in the heater, in-
cluding both eld and factory installed connec-
tions, for tightness before operating the heater.
After a short period of operation, check all con-
nections again for tightness.
DO NOT operate electric heat below the
minimum airow requirement.
AIR FLOW REQUIREMENTS
2. Visually inspect the heater elements prior to us-
ing the heater. If physical damage is evident, use
a Megohm test to validate that the heater ele-
ments are safe to use. If a less than 10 megohms
is achieved, replace any damaged elements or ce-
ramic insulators prior to operation.
3. Ensureltersareclean,andairowisatthemini-
mum requirement or greater, preferably 100 %
airowforthisstartupprocedure.
4. Make sure all associated control equipment is
turned on.
5. Energize main supply disconnect and set control-
ling thermostat above ambient temperature.
6. This heater is equipped with automatic and manu-
al reset temperature limiting controls. If it fails to
operate, make sure the manual resets are operative
by pushing reset buttons.