Reznor CL31 User manual

Revision: OPT-CL31,32 (08-23) 1042699-B
RELAY KIT INSTALLATION FOR MULTIPLE UNIT CONTROL
Supersedes: OPT-CL31,32 (05-23) 1042699-A
LDAP-CL31,32 (05-23) 1041278-B
OPTIONS CL31 AND CL32 FOR
ELECTRIC UNIT HEATER MODEL EUH,
DESTRATIFICATION FAN MODEL H,
GAS-FIRED DOWNFLOW HEATER MODEL LDAP, AND
GAS-FIRED UNIT HEATER MODELS UBX, UBZ, UDX, UDZ, AND UEZ
⚠ CAUTION ⚠
• DO NOT use these multiple unit control options with a two-stage thermostat.
• These instructions are designed to assist a qualified electrician in installing this multiple unit
control kit. For maximum safety, the control is installed in the low voltage circuit. Interruption
of the supply voltage is not recommended.
• All electrical wiring and connections, including electrical grounding, MUST be in accordance with
the National Electric Code ANSI/NFPA No. 70 (latest edition) or, in Canada, with the Canadian
Electrical Code, Part 1, CSA Standard C22.1. In addition, the installation must comply with local
ordinances and applicable gas company requirements.
RELAY KITS
NOTE: Option CL31 includes components for one control unit and one additional unit. Option
CL32 includes components for each additional non-control unit. Not all kit components will be
used on all models.
• These relay kits are designed to permit the control of up to five units (one control unit and up to four additional
non-control units) with one single-stage thermostat or with a time clock and one or more single-stage thermostats.
• Refer to the installation manual provided with the unit for important safety information.
• Ensure that all components listed in Table 1 are available before beginning installation.
Table 1. Relay Kit Components
Item
No.*Component Description
Option
CL31 CL32
Model
LDAP H, UBX,
UBZ
EUH
(208V,
240V)
EUH
(480V)
UDX, UDZ,
UEZ LDAP
EUH, H,
UBX, UBZ,
UDX, UDZ,
UEZ
Kit PN
1041280 1041281 1042927 1042928 1041288 1041286 1041287
Component PN (Quantity)
1 Assembly Relay** 208365 (2) — 208365 (1) —
2 Relay 18549 (2) 18549 (1)
3 Bracket Relay — 197157 (2) — 197157 (1)
4 Screw 38529 (4) 195249 (4) 38529 (2) 195249 (2)
5 Cable clamp 3/16 — 16228 (2) — 16228 (1)
6 Label Wiring diagram 197164 (2) 197164 (1)
7 Transformer 40VA —621709 (1) 202661 (1) 194808 (1) —
8 Wiring harness Assembly 1042929 (1) 197160 (1)
*See Figure 1, Figure 2, Figure 3, Figure 4, Figure 5, and Figure 6.
**Includes relay(s) (item 2), 24VAC DPDT plug(s) (PN 211411), and socket(s) with wires and terminals (PN 211415). If replacing a
previously-used relay only (PN 98118) on an LDAP unit, order replacement kit PN 263527.
DO NOT DESTROY. PLEASE READ CAREFULLY. KEEP IN A SAFE PLACE FOR FUTURE REFERENCE.

2OPT-CL31,32 (08-23) 1042699-B
INSTALLATION
Install the relay kit as follows. Item numbers in parentheses refer to Table 1.
1. For gas-fired units, turn OFF gas and electric power. For electric units, turn OFF electric power.
2. Install/replace transformer (if required) on control unit:
a. For electric unit heater model EUH:
(1) Remove control compartment access panel.
(2) Position transformer (7) as shown in Figure 1, DETAIL A and secure transformer using self-tapping
screws (4).
(3) Connect wires for transformer (7) in accordance with Figure 1, DETAIL B.
(4) Install control compartment access panel
Figure 1. Transformer Location (Typical) and Wiring—Model EUH (Refer to Table 1)
b. For gas-fired unit heater models UDX, UDZ, and UEZ:
(1) Remove control compartment access panel and locate existing transformer (see Figure 2) mounted on
control board at bottom of control compartment for unit size 130–310 UEZ and all UDX and UDZ models.
(2) Mark and disconnect transformer wires
(3) Remove screws that secure existing transformer and remove transformer.
(4) Install replacement transformer (7) with wiring harness (8) and secure using existing screws.
(5) Reconnect transformer wires in accordance with wiring diagram provided with unit.
(6) Install control compartment access panel.
4
7
8
DETAIL B
DETAIL A

3
OPT-CL31,32 (08-23) 1042699-B
2
4
7
7
UEZ (055–110)
7
UDX, UDZ (150–400)
UEZ (130–310)
UDX, UDZ (030–125)
Figure 2. Transformer Location—Models UDX, UDZ, and UEZ (Refer to Table 1)
3. Install relay on control unit and on all non-control units:
a. For electric unit heater model EUH (see Figure 3):
(1) At rear of heater, remove and save screws from edge of cabinet bottom.
(2) Secure relay bracket (3) with relay (2) as shown using existing screws.
(3)
Figure 3. Relay Installation—Model EUH (Refer to Table 1)
b. For destratification fan model H, secure relay (2) as shown in Figure 4 using two screws (4).
Figure 4. Relay Installation—Model H (Refer to Table 1)
EXISTING
SCREWS
32

4OPT-CL31,32 (08-23) 1042699-B
INSTALLATION—CONTINUED
c. For gas-fired downflow heater model LDAP:
(1) Remove control compartment access panel from main heat section.
(2) Position relay assembly (1) as shown in Figure 5 and secure using screws (4).
(3) Install control compartment access panel.
Figure 5. Relay Installation—Model LDAP (Refer to Table 1)
d. For gas-fired unit heater models UBX, UBZ, UDX, UDZ, and UEZ (see Figure 6):
(1) At rear of heater, remove and save screws from edge of cabinet bottom.
(2) For model UBX, UBZ, UDX, and UDZ unit sizes 150–400 and all UEZ models, align relay bracket (3) as
shown and use bracket as template to drill hole in edge of cabinet bottom as shown.
(3) Secure relay (2), relay bracket (3), and cable clamp (5) as shown using existing screws for model UBX,
UBZ, UDX, and UDZ unit sizes 030–125 or one existing screw and one screw (4) from kit for model UBX,
UBZ, UDX, and UDZ unit sizes 150–400 and all UEZ models.
1
4

5
OPT-CL31,32 (08-23) 1042699-B
2
3
EXISTING
SCREWS
5
UBX, UBZ, UDX, UDZ (030–125) UBX, UBZ, UDX, UDZ (150–400)
UEZ (055–310)
4
5
2
3
DRILL
Figure 6. Relay Installation—Models UBX, UBZ, UDX, UDZ, and UEZ (Refer to Table 1)
4. Determine control wiring configuration. Do not exceed length and distance listed in Table 2.
Table 2. Control Wiring Specifications
Gauge Maximum Length*Maximum Distance
Feet (Meters)
12 2100 (640) 1050 (320)
14 1300 (457) 650 (198)
18 500 (152) 250 (76)
*For complete circuit.
⚠ CAUTION ⚠
Be careful NOT TO short thermostat leads to a metal surface. Doing so will cause the transformer
to fail and require replacement.
5. Connect relay (2) to TEW-type control wiring in accordance with Figure 7.

6OPT-CL31,32 (08-23) 1042699-B
INSTALLATION—CONTINUED
e.
Figure 7. Multiple Unit Control Wiring Diagram
6. Install wiring diagram label:
a. For future reference, check appropriate box—for CONTROL UNIT or NON CONTROL UNIT—on wiring
diagram label (5).
b. Determine wiring diagram label position.
c. Wipe surface with clean, dry cloth.
d. Remove label backing and adhere label to unit.
7. Restore system to service:
a. For gas-fired units, turn ON gas and electric power. For electric units, turn ON electric power.
b. Check for proper operation.

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OPT-CL31,32 (08-23) 1042699-B
NOTES

Specifications and illustrations subject to change without notice or incurring obligations.
Latest version of this manual is available at www.reznorhvac.com.
©2023 Nortek Global HVAC LLC, O’Fallon, MO. All rights reserved.
OPT-CL31,32 (08-23) 1042699-B